[1415]*1415HOLLOWAY, Circuit Judge.
This is an appeal brought by defendant L & N Consultants, Inc. from a judgment awarding $47,458.90 for the recovery of real estate brokerage fees and $9,500 for attorney’s fees to plaintiff, J. R. Fulton, d/b/a J. R. Fulton & Company.
I
Plaintiff Fulton, a licensed Oklahoma real estate broker, entered into a real estate brokerage agreement with defendant L & N to be effective from December 10, 1975 until June 10, 1976 covering certain commercial property in Oklahoma City, Oklahoma. Specifically the agreement concerned the sale of a large warehouse building plus 23 acres of vacant land known as the “Plaza III Industrial Park.” Subsequently these parties entered into a supplemental agreement which extended the listing agreement to December 10, 1976. The supplemental agreement extended the previous agreement under the same terms and conditions except that it provided that if the property was sold to a non-Oklahoma entity by the defendant without any assistance from the plaintiff, the plaintiff would be entitled to a three percent commission.1 This was a commission reduction from that provided by the original exclusive contract, which called for the payment of a six percent commission, regardless of who sold the property. (II R. Pl. Exs. 1 and 2).
During the term of the supplemental listing agreement defendant L & N began negotiations with one Stanley Robert Fimberg concerning the sale of the Plaza III property. The progress of the negotiations is a matter in dispute but there is evidence that these discussions began in September 1976. As the negotiations continued it became clear that the parties contemplated that a limited partnership would be syndicated by Mr. Fimberg and that the partnership would be the purchaser of the property. Subsequently, Mr. Fimberg formed a limited partnership known as Vermont Street Associates, Ltd., on December 14, 1976. Defendant L & N and Vermont Street Associates, Ltd., executed a written agreement for the sale of the Plaza III property. This agreement stated that it was “made and entered into as of the 1st day of September, 1976.”2 In addition a promissory note, a mortgage-security agreement, and a warranty deed were executed. The mortgage-security agreement recites that it is executed “as of the 1st day of September, 1976, on this 16th day of December, 1976.” In addition, the promissory note recites that it was “to be executed as of the day and year first above written” that day being September 1, 1976.
Plaintiff Fulton brought this action in the district court asserting two causes of action in the alternative. In the first cause of action judgment was sought in the sum of $72,000 for the failure of defendant to accept a purchaser procured by the plaintiff Fulton for the Plaza III property, plus interest, costs, and attorney’s fees. On the second cause of action judgment was sought for $41,310.00, plus costs and attorney’s fees, for the failure of defendant L & N to pay a three percent commission on the sale of defendant’s property to a non-Oklahoma entity without the assistance of plaintiff. [1416]*1416The trial court granted defendant’s motion to dismiss as to plaintiff’s first cause of action, but overruled the motion as to the second cause of action.
The defendant asserted that recovery should not be had by plaintiff for the reasons that there was no sale within the life of the listing agreement and, in any event, the plaintiff was not the procuring cause of the sale.
The second cause seeking the real estate commission was tried to the court. The main issue at trial was whether the agreement of sale was executed by December 10, 1976, so as to be within the life of the extended listing agreement. There was no claim by plaintiff that defendant L & N and Vermont Associates delayed execution of the agreement of sale so as to permit the brokerage agreement to expire. (III R. 29-30).
During trial, the court sustained an objection by plaintiff Fulton to defendant L & N’s evidence concerning when the agreement of sale was executed and what terms remained open for negotiation after expiration of the brokerage agreement on December 10, 1976. This objection was sustained on the basis of the parol evidence rule. In a memorandum opinion granting judgment for the commission and attorney’s fees to plaintiff Fulton, the trial court found that plaintiff was not a stranger to the contract because his rights were affected thereby and that he could properly object to the admission of parol evidence. (I R. 295). The court found further that
The Agreement of Sale between the defendant and Vermont Streets Associates, Ltd., is complete and unambiguous. The contract reflects the date of execution to be September 1, 1976. No conflicting date is apparent in the instrument. The date is not ambiguous, but clear from the four corners of the document. In this instance, the date of execution is a material element of the contract. Parol evidence is thus inadmissible to vary or contradict the date of execution. (I R. 297).
The court further held in the alternative that the defendant’s offer of proof “is insufficient, in the face of the evidence presented, including the written agreement, to dissuade the Court from its finding that the Agreement of Sale was agreed upon and executed within the term of the extended listing agreement.” (I R. 297). The court noted that “defendant’s offer of proof included examination of a witness, including cross-examination by plaintiff, and the submission of numerous documents. The record thus appears to be as complete as though the Court had reserved ruling on the parol evidence issue until after trial.” (I R. 295).
It was also found that this sale was accomplished without plaintiff’s assistance and that under the extended listing agreement, plaintiff Fulton was entitled to a commission of three percent of the sale price, and interest. Finally the court held that plaintiff is entitled to recover attorney’s fees under 12 O.S.1971 § 936 because this was an action to recover for the services of a real estate broker.
On appeal, defendant L & N argues that plaintiff was not entitled to the commission under the brokerage agreement which expired before execution of the agreement of sale, claiming error in (1) the exclusion of evidence as to the date of actual execution of the agreement of sale and as to when agreement was reached on all essential terms of the contract; (2) the finding that an enforceable agreement of sale existed on or before December 10, 1976, which is clearly erroneous; and (3) in awarding attorney’s fees to the plaintiff and in doing so without a proper hearing.
II
As noted, the trial judge made two key rulings which led to the entry of judgment for plaintiff Fulton. First, on the basis of the parol evidence rule he rejected proof offered to show that the agreement for sale of the Plaza III property was not actually entered into until after expiration of the [1417]*1417brokerage agreement on December 10,1976. In evidence there remained the Agreement of Sale which recited that the agreement was “made and entered into as of the 1st day of September, 1976 .... ” Second, the trial judge alternatively held that the offer of proof was insufficient in any event to dissuade him from his finding that the agreement of sale was agreed on and executed within the term of the extended listing agreement.
The offer of proof, which was excluded, was made in the following manner. Mr. Brannian, an attorney of Dallas, Texas, who represented Mr. Fimberg, was first permitted to testify. Further, the attorney for defendant L & N stated on the record an offer of proof as to what the testimony would be by Mr. Lucas, an attorney who represented L & N in connection with the sale, and by Mr. Fimberg, the general partner of Vermont Associates. In addition, several documents were tendered, all showing execution dates of December 15 or 16, 1976, after expiration of the extended brokerage agreement. This entire offer of proof was excluded by the trial judge.
In his testimony Mr. Brannian, the Dallas attorney, discussed the execution of the agreement of sale. He said’ that he witnessed the execution of the agreement in Dallas by Mr. Fimberg for Vermont Associates, the purchaser, on December 16, 1976. He testified that an all-inclusive mortgage-security agreement, a warranty deed and an all-inclusive promissory note (Defendant’s Exhs. 13, 14 and 15) were all executed at the same time as the agreement of sale on December 16, 1976.
Mr. Brannian stated further that material terms of the contract had not been agreed on as of December 10. More specifically, he said that terms for the payment of additional consideration of $150,000, the form of the mortgage, liability for payment of certain sums due under the promissory note, a non-competition agreement, and the question whether the property could be sold without the mortgagee’s consent, had not been agreed on before expiration of the brokerage agreement on December 10. (Ill R. 58-59). Further Mr. Brannian said that until Vermont Associates had filed its articles of limited partnership with the Secretary of State, it could not complete the sales transaction; until the limited partners contributed the capital, the purchase could not be made. (Ill R. 59-60).
On cross-examination, it was developed that Mr. Brannian had testified by deposition that the “basic” terms of the sale had been agreed on in September or early October, 1976, and that such terms included the purchase price and manner of payment. In addition, Mr. Brannian admitted that the “concept of paying $150,000, based upon a cash flow, had been agreed to” as of September 17, but “[t]he manner of determination of the cash flow and how that was determined ... and what cash flow was” had not been determined. Lastly, it was brought out that the purchase price proposed earlier turned out to be the exact amount called for in the closing of the transaction. (III R. 61-64).
In addition, an offer of proof was made as to what the testimony would have been by Mr. Lucas, an attorney representing L & N, if he had been permitted to testify. Defense counsel said that Mr. Lucas would testify that he was present in Dallas on December 16 when the agreement of sale and all the related documents were executed at the same time as part of the same transaction; that as of December 10, the conditions of the $150,000 note had not been agreed on and consent of the first mortgage holder to sale of the property had not been received. (III R. 69, 70). Defendant L & N further offered to show that Mr. Fimberg would have testified that the agreement of sale and other closing documents were executed on December 15 and 16, 1976; that the agreement was back dated for tax purposes.
Lastly, defendant L & N offered the certificate and articles of limited partnership, stating that the partnership was prohibited [1418]*1418from conducting business in Oklahoma; that under the terms of the agreement the limited partnership would not exist until the articles were filed with the Secretary of State in Texas. The certificate and articles of limited partnership filed in Texas were offered, reflecting they were not filed until December 14, 1976.
It was this offer of proof, as detailed above, which was excluded on the basis of the parol evidence rule, to which we now turn.
III
Defendant argues first that the evidence offered, by which it sought to establish that the agreement of sale was not actually executed until after expiration of the extended listing agreement, was erroneously excluded. It contends that the plaintiff, as a third party to the contract between it and Vermont Associates, was not entitled to invoke the parol evidence rule and that in any event such evidence, showing merely the true execution date, was not barred by the rule.
The parol evidence rule in Oklahoma is embodied in 15 O.S.1971 § 137, which provides:
§ 137. Writing excludes oral negotiations or stipulations
The execution of a contract in writing, whether the law requires it to be written or not, supersedes all the oral negotiations or stipulations concerning its matter, which preceded or accompanied the execution of the instrument.3
The general rule in Oklahoma is that the parol evidence rule only applies to parties to the agreement and their privies. In Re Assessment of Alleged Omitted Property, 177 Okl. 74, 58 P.2d 134, 137; In Re McClain, 447 F.2d 241, 244 (10th Cir.), cert, denied, 405 U.S. 918, 92 S.Ct. 943, 30 L.Ed.2d 788 (applying Oklahoma law); Trane Company v. Bearden Plumbing and Heating Company, 463 P.2d 350, 352 (Okl.).4 The parol evidence rule has been relaxed where a stranger to the writing is involved. 3 Corbin, Contracts § 596 (1960). Moreover, it has generally been held that the parol evidence rule does not apply in cases where real estate brokers are suing for commissions and where the rule is invoked to confine the evidence to the written contract between the principal and the purchaser. 32A C.J.S. Evidence § 861 (1964).
Furthermore, it has been held that parol is admissible to show the date of execution [1419]*1419of a deed conveying land when such date is in dispute. Randolph v. Mullen, 73 Okl. 199, 175 P. 512, 513; see Kilgore v. Parrott, 197 Okl. 77, 168 P.2d 886, 889 (parol proof admissible as to whether there was actual delivery of a deed of conveyance); In re Spencer’s Inc., 61 Wash.2d 267, 377 P.2d 880, 884 (parol proof admissible as to date of actual taking of possession by vendee on date other than contract date); 3 Corbin, Contracts § 577 (1960).5 Here the agreement does not state that it was executed on any given date and its recitation that it was “[m]ade and entered into as of the 1st day of September, 1976” (emphasis added), which could well serve other purposes, leaves the date of actual execution undecided.6 See United States v. Munro-Van Helms Co., 243 F.2d 10, 13 (5th Cir.); Matter of Prior Bros. Inc., 29 Wash.App. 905, 632 P.2d 522, 526. Moreover, even if the recital were viewed as stating that actual execution of the agreement of sale occurred on September 1, 1976, “[a] recital of a fact in an integrated agreement may be shown to be untrue.” Restatement (Second) of Contracts § 218(1) (1981).7 Thus evidence to prove the true date of execution is admissible without violation of the parol evidence rule.
In sum, we conclude that it was error to sustain the parol evidence objection by the real estate broker to evidence attempting merely to establish the actual date of execution of the agreement of sale. Nor can we agree with the court’s reasoning that the plaintiff broker was “affected” by the Agreement of Sale to the extent that he could invoke the rule. The broker was not a party to the contract of sale and he was not in privity with a party to the agreement. Therefore, plaintiff had no such relationship to the contract and no such interest in the integrity of its terms as to entitle him to invoke the exclusionary rule.
IY
We feel that defendant’s offer of proof did tender a plausible basis for findings that a binding agreement of sale was not entered into within the life of the extended listing agreement and that the commission was not due. We conclude that it was error to exclude the offer of proof and we remand, as further explained below.
The trial court held that “the factor determining whether the plaintiff is entitled to his commission is whether an enforceable agreement for sale had been reached within the term of the contract.” (I R. 297). We agree with this interpretation of plaintiff’s rights under the provision of the extended listing agreement for a commission “[i]f any of the property is sold...” by L & N without Fulton’s assist[1420]*1420anee to a non-Oklahoma entity. Note 1, supra; see Gilliland v. Jaynes, 36 Okl. 563, 129 P. 8, 10 (commission due if the purchaser and vendor enter into a “valid, binding, and enforceable contract”).8 It was critical, therefore, that an enforceable written agreement be shown to have been executed by December 10 for the commission to have been due. The offer of proof clearly dealt with this issue.
It is true that there was testimony, which the trial court was free to accept, that there were negotiations and that oral agreements were made before expiration of the extended listing on December 10. There was testimony that plaintiff was contacted by Tom Dodds, a loan officer of L & N Consultants, concerning the making of an agreement for sale well before expiration of the extended listing agreement. Plaintiff Fulton testified that
all during the period of October, the end of October and November [Tom Dodds] had informed me that a sale was agreed upon, that the closing was imminent and on two or three different occasions said it was going to happen the following Monday morning. (VI R. 20, 21).
When asked why Mr. Dodds contacted him in the first place, plaintiff replied that
Mr. Dodds had rejected our contract that we had because he had a substantially better offer. He came by to tell us that the sale was made, the closing documents were being prepared and he wanted to negotiate the actual amount of commission that J. R. Fulton was to receive because of other provisions in the contract which would change the consideration, the total consideration. (VI R. 22, 23).
This first meeting regarding the sale of the property took place at the end of September or the first of October. (VI R. 22).
Plaintiff testified further that his company continued negotiations with certain prospective purchasers for the sale of the property after October 1, 1976, although it terminated its advertising effort in early October upon learning that for all practical purposes the property had been sold. (VI R. 40, 43-44). He testified that his company had a policy of continuing on with the prospects until the closing date as a matter of course and that he was never advised that the purchaser may have been having problems raising the necessary capital. (VI R. 40, 41). Plaintiff testified that he was first notified that the deal had been closed by Mr. Dodds on December 10th or 11th.
Mr. Dodds testified that as of September 17, 1976, the full purchase price for the property had been determined. He said that as of October the major business as[1421]*1421pects of the deal had been agreed on. He conceded that he probably told plaintiff in October 1976 to abandon his sales efforts because the property had been sold. (V R. 22-47).
Nevertheless, the testimony admitted and offered did not conclusively establish that the execution of the agreement of sale occurred on or before December 10. The evidence pointing to the September 1, 1976, date was the recitation in the Agreement of Sale that it was “made and entered into as of the 1st day of September, 1976” and similar recitations in other instruments of effectiveness “as of” September 1 and testimony outlined above. And we note again that the plaintiff broker did not claim that defendant L & N and the purchaser delayed execution of the agreement of sale so as to permit the brokerage agreement to expire. (III R. 29-30).
We conclude that the offer of proof was sufficient to support a finding that the actual execution of the agreement of sale did not occur during the life of the listing agreement, contrary to the finding made. Although the trial judge’s memorandum states that the offer of proof was insufficient to dissuade him from finding that the agreement was made on September 1, his basis for this is not clear, i.e., whether the judge refused to accept and believe the proffered evidence indicating that the date of actual execution was after expiration of the listing agreement, or whether the written Agreement of Sale with its recitation of being made and entered into “as of” September 1 was viewed as conclusive that the actual date of execution was September 1. The latter view seems more likely to have been the basis of the ruling in light of the court’s statement that the “contract reflects the date of execution to have been September 1, 1976.”
In any event, the ruling on the parol evidence objection resulted in a determination on the crucial date of actual execution without the trial judge observing two witnesses, Messrs. Lucas and Fimberg,
In this connection we add this clarifying comment. We are not holding that plaintiff’s commission would not be due just because some of the closing documents, such as a conveyance, were not executed during the life of the extended listing agreement. If an enforceable agreement of sale is found to have been executed during that period, then under this listing agreement and the theory the plaintiff has relied on, the commission would be due.
y
Due to the fact that attorney’s fees for the prevailing party will likely need to be determined again on remand, we will also address claims of error in the awarding of attorney’s fees, despite the fact that we must set aside the judgment for reasons already given.
The trial court awarded attorney’s fees to the plaintiff in the amount of $9,500.00. Defendant argues that this case is not a proper one for the recovery of any attorney’s fees, that there was insufficient evi[1422]*1422dence to justify the award, and that in any event it was entitled to a hearing on this issue instead of a determination on an inadequate affidavit. We agree with the trial court that this is a proper type of case for the award of fees. We conclude, however, that there should be a hearing to determine a proper fee, with more complete evidence called for by the Oklahoma law on the award of such fees.
The award of attorney’s fees is authorized by 12 O.S.1971 § 936 in actions for recovery of compensation “for. labor or services,” inter alia.9 The right of a real estate broker to recover attorney’s fees under the statute has been recognized. See Bentley v. Hardin, 577 P.2d 471, 475 (Okla. Ct.App.);10 Bache & Co. v. Clay, 366 F.Supp. 1248, 1251 (W.D.Okla.). Defendant argues that the plaintiff did not render any services in connection with the sale of the property to Vermont Associates and is not entitled to recover attorney’s fees. We agree with the trial court that this action was one to recover for services of a real estate broker and that fees were recoverable, despite the provision for calculation of a fee if the property was sold without the broker’s services.
The question remains as to whether an evidentiary hearing should have been held on the fees. Before the court’s memorandum opinion was filed an affidavit was submitted by the plaintiff which furnished some general information on the services of plaintiff’s attorney.11 In his memorandum opinion the trial judge determined that the plaintiff was entitled to attorney’s fees and ordered the defendant to submit a response within ten days on the amount of the fee. In its response defendant objected to the determination being made without a hearing and asserted that there was insufficient information in plaintiff’s affidavit for determining the fee. (I R. 301).
Without a hearing or further proceedings the trial judge entered an order pointing out that judgment had been awarded to plaintiff, with interest, in the amount of $47,458.90, that plaintiff’s counsel had furnished an affidavit showing that 125 hours had been spent in prosecuting the case, that the court had knowledge of the facts by presiding over various proceedings; and that in accord with Rule 78, F.R.Civ.P. and Local Rule 13(a), the fee should be determined, and plaintiff was awarded $9,500 in attorney’s fees.
We must agree that the evidentiary hearing requested by defendant should have been held. See Del Rey Air v. Expressway Airpark, Inc., 468 F.2d 187, 189 (10th Cir.), (applying 12 O.S.1971 § 936); Salone v. United States, 645 F.2d 875, 878 (10th Cir.), cert, denied, 454 U.S. 894, 102 S.Ct. 390, 70 L.Ed.2d 208; Matter of Permian Anchor Services, Inc., 649 F.2d 763, 768 (10th Cir.). The necessity for such an evidentiary hearing was not obviated by the provisions on motion days in Rule 78, F.R.Civ.P., permit[1423]*1423ting disposition of motions on written statements without oral hearings, as implemented by Local Rule 13(a).
Moreover the Oklahoma Supreme Court has identified the key factors to be considered in awarding attorney’s fees in State ex rel. Burk v. City of Oklahoma City, 598 P.2d 659, 661 (Okla.), naming several not covered in the information furnished to the trial court here. See also Oliver’s Sport Center, Inc. v. National Standard Ins., 615 P.2d 291, 294-95 (Okla.). The Oklahoma Court pointed to the enumeration of these factors in Johnson v. Georgia Highway Express, Inc., 488 F.2d 714 (5th Cir.).12 Our court has also relied on the same factors. See Salone v. United States, supra, 645 F.2d at 879; Battle v. Anderson, 614 F.2d 251, 258 (10th Cir.). On remand, an evidentiary hearing should be held for the presentation of evidence on these and other factors the trial court deems proper in determining the award of attorney’s fees for the prevailing party.
The judgment is reversed and the case is remanded for further proceedings in accord with this opinion. On remand, the district court should afford a hearing for the presentation of evidence by the parties as to whether an enforceable agreement of sale of the subject property was made at a time entitling the plaintiff-appellee to a commission; and the court should permit introduction of evidence on any further theory for recovery of a commission under the agreement of the parties and state law, if amendment is made to plead such an additional theory for recovery. After a determination is made on the recoverability of a commission, a hearing should be held on the allowance of proper attorney’s fees to the prevailing party.
. Mr. Fimberg’s deposition, which addressed the date of actual execution, was offered by plaintiff and admitted in connection with defendant’s offer of proof. Nevertheless, as noted in the text, the judge did not observe the witness and have the impact of the testimony before him.