F I L E D
                                                                   United States Court of Appeals
                                                                           Tenth Circuit
                     UNITED STATES COURT OF APPEALS
                                                                           JAN 31 2002
                            FOR THE TENTH CIRCUIT
                                                                      PATRICK FISHER
                                                                               Clerk

    GAMBLE, SIMMONS & COMPANY,

                Plaintiff-Appellee,

    v.                                             Nos. 00-6062 & 00-6306
                                                   (D.C. No. 95-CV-256-C)
    KERR-MCGEE CORPORATION,                              (W.D. Okla.)

                Defendant-Appellant.


                            ORDER AND JUDGMENT            *




Before SEYMOUR , Circuit Judge, BRORBY , Senior Circuit Judge, and
BRISCOE , Circuit Judge.




         After examining the briefs and appellate record, this panel has determined

unanimously to grant the parties’ request for a decision on the briefs without oral

argument. See Fed. R. App. P. 34(f); 10th Cir. R. 34.1(G). The cases are

therefore ordered submitted without oral argument.




*
      This order and judgment is not binding precedent, except under the
doctrines of law of the case, res judicata, and collateral estoppel. The court
generally disfavors the citation of orders and judgments; nevertheless, an order
and judgment may be cited under the terms and conditions of 10th Cir. R. 36.3.
       Kerr-McGee Corporation appeals from the district court’s orders granting

summary judgment in favor of Gamble, Simmons & Company (Gamble Simmons)

on Gamble Simmons’ complaint, awarding Gamble Simmons prejudgment

interest, and vacating its earlier award of attorney’s fees to Kerr-McGee as

a prevailing party.

       This case is before us for a second round of appellate consideration. Most

of the pertinent facts are recited in our prior opinion in the case,   Gamble,

Simmons & Co. v. Kerr-McGee Corp.          , 

(10th Cir. 1999), and we do

not repeat them in detail here.

       Gamble Simmons sued Kerr-McGee to recover sums allegedly due for tax

consulting services. Gamble Simmons performed the services under a contract

which called for Gamble Simmons to review sales and use tax assessments for the

years 1982-84 issued to Kerr-McGee by the Louisiana Department of Revenue

and Taxation (Department). Under the terms of the contract, Kerr-McGee agreed

to compensate Gamble Simmons in

       an amount equal to forty percent (40%) of the amount, if any, by
       which the total amounts of taxes, penalties and/or interest calculated
       through the date of this Agreement heretofore paid by Kerr-McGee to
       its vendors, the State of Louisiana and/or assessed by the Department
       but remain unpaid as of the date hereof, are refunded or reduced[.]

Appellant’s App., Vol. I at 28-29.




                                              -2-
      Gamble Simmons obtained a very favorable outcome for Kerr-McGee.

After Gamble Simmons completed its examination, the Department admitted not

only that Kerr-McGee owed no additional taxes or interest for the years 1982-84,

but that it had actually overpaid taxes in the amount of $1,447,985. Rather than

refunding this entire amount directly to Kerr-McGee, however, the Department

refunded a portion of the amount and applied the remainder to offset taxes and

interest that Kerr-McGee owed for 1985-87. The use of this offset has created

a significant disagreement between the parties about computation of Gamble

Simmons’ compensation.

      In our previous decision, we determined that Gamble Simmons was not

entitled to compensation for any refund of payments Kerr-McGee made to the

Department after the date of the agreement.         1
                                                        We noted, however, that the district

court’s order was problematic on this point, “because it does not specifically

address the issue of the alleged post-agreement payments, or sufficiently explain


1
       Our previous decision in this matter came after the district court entered a
final judgment granting Kerr-McGee’s motion for summary judgment and
awarding Gamble Simmons $665,418 for its services–“the exact amount
Kerr-McGee had already paid.”     Gamble, Simmons , 175 F.3d at 766. In that
decision, we also determined that (1) the contract was unambiguous; (2) Gamble
Simmons was not entitled to any portion of statutory interest the Department of
Revenue included as part of the refund; (3) Gamble Simmons was not entitled to
forty percent of interest reductions Kerr-McGee realized in the 1985-87 audit
period through application of the 1982-84 tax refund; and (4) Gamble Simmons
was not entitled under the contract to examine Kerr-McGee’s records for years
subsequent to 1982-84, except to the extent incidental to the 1982-84 audit.

                                              -3-
its rationale for determining that Kerr-McGee only owes Gamble Simmons what

it had previously paid.”   

We therefore remanded

       for further proceedings with regard to the discrete issue of the
       post-agreement payments and their effect on the ultimate calculation
       of Gamble Simmons’ compensation. On remand, the district court
       should afford the parties the opportunity to present evidence on the
       issue of the disputed post-agreement payments and provide a final,
       accurate calculation of Gamble Simmons’ compensation based on our
       rulings in this case.

       On remand, the district court received further evidence and conducted

further proceedings on the issue of post-agreement payments. The parties

essentially agreed on the figures for post-agreement payments, but disagreed

radically on how those payments should be treated under the contract and under

the scope of our mandate. The district court concluded:

       Kerr-McGee’s post-agreement payments were reduced by application
       of the tax credit generated by Gamble Simmons. Therefore, it falls
       within the class of items on which Gamble Simmons’ contingency fee
       must be calculated. It is a reduction in taxes that was generated
       during the audit period.

       Based on this finding, the district court awarded Gamble Simmons

compensation on the post-agreement payments. Kerr-McGee contends that this

finding exceeded the scope of the mandate we issued in our previous opinion.

We agree.


                                         -4-
      “This court is vested with the authority to interpret its own mandate.”

Burton v. Johnson , 

, 693 (10th Cir. 1992). “Under [the law of the

case] doctrine, once a court decides an issue, the same issue may not be

relitigated in subsequent proceedings in the same case. An important corollary of

the doctrine, known as the ‘mandate rule,’ provides that a district court must

comply strictly with the mandate rendered by the reviewing court.”   Ute Indian

Tribe v. Utah , 

, 1520-21 (10th Cir. 1997) (quotations and citations

omitted).

      In our previous decision, we specifically held that Kerr-McGee was entitled

to exclude post-agreement payments from the calculation of Gamble Simmons’

compensation:

      Kerr-McGee claims it has paid Gamble Simmons everything it owes,
      and explains the relatively small monetary difference between the
      amount it paid and the amount Gamble Simmons requests as
      attributable to certain “post-agreement payments” it made to the state
      of Louisiana. Kerr-McGee claims it made these payments to satisfy
      tax liabilities arising from Department audits encompassing the years
      1985-1987, and that the Department later refunded the payments after
      it determined Kerr-McGee had overpaid its tax liabilities for
      1982-1984. Kerr-McGee argues that because it made the payments
      after contracting with Gamble Simmons, it need not include these
      amounts in its compensation calculations. In support of this claim,
      Kerr-McGee cites the terms of the contract which limit Gamble
      Simmons contingent interest to forty percent of any refund or
      reduction of amounts paid or assessed as of the date of the
      agreement.




                                           -5-
             We agree with Kerr-McGee to the extent that the contract
      unambiguously limits Gamble Simmons’ compensation to payments
      or assessments made prior to the execution of the agreement . . . .
      Gamble Simmons has no viable claim under the strict contractual
      language to any refund of payments Kerr-McGee made, if any,
      subsequent to the agreement date. The contract is clear on this point,
      and its interpretation is properly the subject of summary adjudication.

Gamble, Simmons , 175 F.3d at 772.

      Under the mandate previously issued in this case, Gamble Simmons’ forty

percent compensation should have been figured only on the amounts Kerr-McGee

paid or was assessed at the time the Agreement was signed. We merely directed

the district court to determine what amount of payments Kerr-McGee made after

May 22, 1991, so that these payments could be excluded from the calculation of

Gamble Simmons’ percentage. The district court went beyond the scope of the

mandate and determined that Gamble Simmons was entitled to compensation for

the post-agreement payments, a finding directly contrary to our prior holding in

the case.

      We therefore reverse the district court’s order awarding judgment in favor

of Gamble Simmons in the amount of $34,760.60. On remand, the district court

should address the specific issue identified in our previous mandate: the amount

of payments Kerr-McGee made subsequent to the date of the agreement and their

effect on the mathematical calculation of Gamble Simmons’ compensation.




                                        -6-
      The remaining issues in this appeal involve whether the district court

properly awarded Gamble Simmons pre-judgment interest and whether it properly

vacated its previous award of attorney’s fees to Kerr-McGee and held that

Kerr-McGee was no longer a prevailing party. Since we have determined the

district court exceeded the scope of its authority in granting judgment in favor of

Gamble Simmons, the pre-judgment interest award must also be vacated. On

remand, the district court should further reconsider its order vacating the award of

attorney’s fees in favor of Kerr-McGee in light of this order and judgment.

      The judgments of the United States District Court for the Western District

of Oklahoma granting judgment in favor of Gamble Simmons in the amount of

$34,760.60, awarding prejudgment interest on that award, and vacating the award

of attorney’s fees in favor of Kerr-McGee are VACATED, and the case is

REMANDED for further proceedings in light of this order and judgment.


                                                    Entered for the Court



                                                    Wade Brorby
                                                    Senior Circuit Judge




                                         -7-