<PAGE>


                                                                    EXHIBIT 99.2


               UNAUDITED PRO FORMA COMBINED FINANCIAL INFORMATION

         On January 28, 2005, Acacia Global Acquisition Corporation, a newly
formed wholly owned subsidiary of Acacia Research Corporation, acquired certain
assets from Global Patent Holdings, LLC, a privately held patent holding company
based in Northbrook, Illinois (the "acquisition"). The assets acquired and
liabilities assumed in the transaction have been attributed to Acacia Research
Corporation's Acacia Technologies group. The acquisition gives the Acacia
Technologies group 100% ownership of companies that control 27 patent
portfolios, which include 120 U.S. patents and certain foreign counterparts, and
cover technologies used in a wide variety of industries. The acquisition is
being accounted for by the purchase method of accounting.

         The following unaudited pro forma combined financial information gives
effect to the acquisition described above. The unaudited pro forma combined
balance sheet as of December 31, 2004, gives effect to the acquisition as if it
had taken place on December 31, 2004. The unaudited pro forma combined statement
of operations for the year ended December 31, 2004, reflects the acquisition as
if it had taken place on January 1, 2004.

         The unaudited pro forma combined financial information, and the
accompanying notes, should be read in conjunction with the historical financial
statements of Acacia Research Corporation as of and for the year ended December
31, 2004, including the notes thereto, which are included in our Annual Report
on Form 10-K filed with the Securities and Exchange Commission on March 15,
2005. The unaudited pro forma combined financial information, and the
accompanying notes, should also be read in conjunction with the December 31,
2004 financial statements of Global Patents Holdings, LLC, including the notes
thereto, included elsewhere herein.

         The estimated purchase consideration and preliminary purchase price
allocation in Note 2 and the preliminary pro forma adjustments in Note 3, are
based upon preliminary estimates and currently available information. Final
purchase accounting adjustments may differ from the pro forma adjustments
presented.

         The unaudited pro forma combined balance sheet and statement of
operations are for informational purposes only. They do not purport to indicate
the results that would have actually been obtained had the acquisition been
completed on the assumed date or for the period presented, or which may be
obtained in the future.


<PAGE>

<TABLE>
                                                     ACACIA RESEARCH CORPORATION
                                             UNAUDITED PRO FORMA COMBINED BALANCE SHEET
                                                       AS OF DECEMBER 31, 2004
                                       (IN THOUSANDS, EXCEPT SHARE AND PER SHARE INFORMATION)


                                                                                                                         ACACIA
                                                                   ACACIA                                               RESEARCH
                                                                  RESEARCH      GLOBAL PATENT      PRO FORMA           CORPORATION
                                                                 CORPORATION    HOLDINGS, LLC     ADJUSTMENTS           PRO FORMA
                                                               --------------   --------------   --------------       --------------
<S>                                                            <C>              <C>              <C>                  <C>
                           ASSETS                                                    (1)

Current assets:
   Cash and cash equivalents ...............................   $      18,735    $       3,673    $      (5,000) (A)   $      13,735
                                                                                                        (3,673) (B)
   Short-term investments ..................................          33,623            1,994           (1,994) (B)          33,623
   Accounts receivable .....................................             536            1,224           (1,224) (C)             536
   Prepaid expenses, inventory and other assets ............             983               86              (11) (B)           1,058
                                                               --------------   --------------   --------------       --------------

         Total current assets ..............................          53,877            6,977          (11,902)              48,952

Property and equipment, net of accumulated
   depreciation and amortization ...........................           2,434               --                                 2,434
Patents, net of accumulated amortization ...................          12,063               93           25,069  (D)          37,225
Goodwill ...................................................          19,545               --                                19,545
Other ......................................................             408              734             (734) (C)             408
                                                               --------------   --------------   --------------       --------------

                                                               $      88,327            7,804           12,433        $     108,564
                                                               ==============   ==============   ==============       ==============

                LIABILITIES AND STOCKHOLDERS' EQUITY

Current liabilities:
   Accounts payable, accrued expenses and other ............   $       4,139    $         649    $         613  (E)   $       5,004
                                                                                                          (397) (E.1)
   Current portion of deferred revenues ....................             494               --                                   494
   Royalties and contingent litigation fees payable ........              --            1,071           (1,071) (C)              --
                                                               --------------   --------------   --------------       --------------

         Total current liabilities .........................           4,633            1,720             (855)               5,498

Deferred income taxes ......................................           2,981               --                                 2,981
Deferred revenues, net of current portion ..................           3,893               --                                 3,893
Royalties and contingent litigation fees payable,
     net of current portion ................................              --              592             (592) (C)              --
Unfunded pension liability .................................              --              138             (138) (E.1)            --
Other liabilities ..........................................             406               --                                   406
                                                               --------------   --------------   --------------       --------------
         Total liabilities .................................          11,913            2,450           (1,585)              12,778
                                                               --------------   --------------   --------------       --------------

Minority interests .........................................             778               --                                   778
                                                               --------------   --------------   --------------       --------------

Commitments and contingencies

Redeemable Stockholders' equity:
   Common stock ............................................
     Acacia Research - Acacia Technologies stock,
       par value $0.001 per share; 50,000,000
       shares authorized; 19,811,524 shares (actual)
       and 23,750,356 shares (pro forma) issued and
       outstanding as of December 31, 2004 .................              20               --                4 (F)               24
     Acacia Research - CombiMatrix stock, par value
       $0.001 per share; 50,000,000 shares authorized;
       31,200,496 shares issued and outstanding as of
       December 31, 2004 ...................................              31               --                                    31
   Additional paid-in capital and accumulated
       comprehensive income ................................         263,823             (138)          19,368 (F)          283,191
                                                                                                           138 (E.1)
                                                                                                               (B),(C),
   Members' Equity .........................................              --            5,492           (5,492)(D),(E.1)         --
   Accumulated deficit .....................................        (188,238)              --                              (188,238)
                                                               --------------   --------------   --------------       --------------

         Total stockholders' equity ........................          75,636            5,354           14,018               95,008
                                                               --------------   --------------   --------------       --------------

                                                               $      88,327    $       7,804    $      12,433        $     108,564
                                                               ==============   ==============   ==============       ==============


</TABLE>
<PAGE>

<TABLE>
                                                     ACACIA RESEARCH CORPORATION
                                        UNAUDITED PRO FORMA COMBINED STATEMENT OF OPERATIONS
                                                FOR THE YEAR ENDED DECEMBER 31, 2004
                                       (IN THOUSANDS, EXCEPT SHARE AND PER SHARE INFORMATION)


                                                                                                                    ACACIA RESEARCH
                                                      ACACIA RESEARCH      GLOBAL PATENT          PRO FORMA            CORPORATION
                                                       CORPORATION         HOLDINGS, LLC         ADJUSTMENTS            PRO FORMA
                                                     ----------------     ----------------     ----------------     ----------------
<S>                                                           <C>                   <C>                 <C>                  <C>
                                                                               (2)
Revenues:
   Research and development contract,
     service contracts and product .............     $        17,648                                                $        17,648
   License fees ................................               4,284               16,767                                    21,051
   Government contract .........................               1,993                                                          1,993
                                                     ----------------     ----------------     ----------------     ----------------
   Total revenues ..............................              23,925               16,767                   --               40,692
                                                     ----------------     ----------------     ----------------     ----------------
Operating expenses:
   Cost of government contract
     revenues and product sales ................               2,047                   --                                     2,047
   Research and development expenses ...........               5,385                   --                                     5,385
   Marketing, general and
     administrative expenses ...................              15,089                1,220                1,000 (G)           17,309
   Legal expenses - patents ....................               3,133                7,061                                    10,194
   Royalties to patent owners ..................                  --                5,385                                     5,385
   Goodwill impairment charge ..................               1,656                   --                                     1,656
   Amortization of patents .....................               1,597                   --                4,129 (H)            5,726
   Legal settlement charges ....................                 812                   --                                       812
                                                     ----------------     ----------------     ----------------     ----------------
     Total operating expenses ..................              29,719               13,666                5,129               48,514
                                                     ----------------     ----------------     ----------------     ----------------
     Operating income (loss) ...................              (5,794)               3,101               (5,129)              (7,822)
                                                     ----------------     ----------------     ----------------     ----------------
Other income (expense):
   Interest income and other expenses ..........                 784                  300                                     1,084
                                                     ----------------     ----------------     ----------------     ----------------
     Total other income (expense) ..............                 784                  300                   --                1,084
                                                     ----------------     ----------------     ----------------     ----------------
Income (loss) from continuing operations
   before income taxes and minority interests ..              (5,010)               3,401               (5,129)              (6,738)
Benefit for income taxes .......................                 275                  (15)                                      260
                                                     ----------------     ----------------     ----------------     ----------------
Income (loss) from continuing
   operations before minority interests ........              (4,735)               3,386               (5,129)              (6,478)
Minority interests .............................                   6                   --                                         6
                                                     ----------------     ----------------     ----------------     ----------------
Income (loss) from continuing operations .......              (4,729)               3,386               (5,129)              (6,472)
                                                     ----------------     ----------------     ----------------     ----------------
Discontinued operations:
   Estimated loss on disposal of
     discontinued operations ...................                (104)                  --                                      (104)
                                                     ----------------     ----------------     ----------------     ----------------

Net income (loss) ..............................     $        (4,833)     $         3,386      $        (5,129)     $        (6,576)
                                                     ================     ================     ================     ================

Pro forma earnings (loss) per common share:
Attributable to the Acacia Technologies group:
  Loss from continuing operations ..............     $        (5,439)     $         3,386               (5,129)     $        (7,182)
    Basic and diluted loss per share ...........               (0.27)                                                         (0.30)
  Loss from discontinued operations ............     $          (104)     $            --                   --      $          (104)
    Basic and diluted loss per share ...........               (0.01)                                                         (0.01)
  Net loss .....................................     $        (5,543)     $         3,386               (5,129)     $        (7,286)
    Basic and diluted loss per share ...........               (0.28)                                                         (0.31)

Attributable to the CombiMatrix group:
Basic and diluted
  Net income (loss) ............................     $           710                                                $           710
    Basic earnings (loss) per share ............                0.02                                                           0.02

Weighted average shares:
  Acacia Research - Acacia Technologies stock:
    Basic and diluted ..........................          19,784,883                                 3,938,832 (I)       23,723,715
                                                     ================                          ================     ================
  Acacia Research - CombiMatrix stock:
    Basic ......................................          29,962,596                                                     29,962,596
                                                     ================                                               ================
    Diluted ....................................          30,995,663                                                     30,995,663
                                                     ================                                               ================

</TABLE>
<PAGE>


NOTES TO THE UNAUDITED PRO FORMA COMBINED FINANCIAL STATEMENTS
(TABULAR DOLLARS IN THOUSANDS, EXCEPT SHARE AND PER SHARE AMOUNTS)

1.       BASIS OF PRESENTATION

         On January 28, 2005, Acacia Global Acquisition Corporation, a newly
formed wholly owned subsidiary of Acacia Research Corporation, acquired certain
assets from Global Patent Holdings, LLC, a privately held patent holding company
based in Northbrook, Illinois (the "acquisition").

         The accompanying unaudited pro forma combined financial statements have
been prepared pursuant to the rules and regulations of the Securities and
Exchange Commission. Certain information and certain footnote disclosures
normally included in financial statements prepared in accordance with accounting
principles generally accepted in the United States of America have been
condensed or omitted pursuant to such rules and regulations; however, management
believes that the disclosures are adequate to make the information presented not
misleading.

         The accompanying unaudited pro forma combined balance sheet as of
December 31, 2004, gives effect to the acquisition as if it had taken place on
December 31, 2004. The unaudited pro forma combined statement of operations for
the year ended December 31, 2004, reflects the acquisition as if it had taken
place on January 1, 2004. The estimated purchase consideration and preliminary
purchase price allocation in Note 2 and the preliminary pro forma adjustments in
Note 3, are based upon preliminary estimates and currently available
information. Final purchase accounting adjustments may differ from the pro forma
adjustments presented.

2.       ACQUISITION OF CERTAIN ASSETS OF GLOBAL PATENT HOLDINGS, LLC

         The acquisition is being accounted for by the purchase method of
accounting. The aggregate purchase consideration was approximately $24,985,000,
including $5,000,000 of cash, the issuance of 3,938,832 shares of Acacia
Research--Acacia Technologies common stock valued at $19,372,000 (net of
estimated common stock registration costs of $133,000) and estimated acquisition
costs of $480,000. The value of the common shares issued was determined based on
the average market price of AR-Acacia Technologies stock, as reported on NASDAQ,
over the 5-day period (December 13 - December 17, 2004) before and after the
terms of the acquisition were agreed to and announced.

          The following table summarizes the total estimated preliminary
purchase consideration (in thousands):

Estimated Purchase Consideration:
Issuance of 3,938,832 shares of Acacia Research - Acacia
  Technologies common stock ........................................    $19,372
  Cash consideration paid ..........................................      5,000
  Acquisition and common stock registration costs ..................        613
                                                                        --------
Total Estimated Purchase Consideration .............................    $24,985
                                                                        ========

         Under the purchase method of accounting, the purchase consideration is
allocated to the assets acquired, including tangible assets, patents and other
identifiable intangibles and liabilities assumed, based on their estimated fair
market values at the date of acquisition. Any excess purchase price after the
initial allocation to identifiable net tangible and identifiable intangible
assets is assigned to goodwill. Amounts attributable to patents are amortized
using the straight-line method over the estimated economic useful life of the
underlying patents. Based on the estimated purchase consideration and the
preliminary valuation, the preliminary purchase price allocation, which is
subject to change based on Acacia Research Corporation's final analysis, is as
follows (in thousands):


<PAGE>

<TABLE>
<S>     <C>
                                                         Amortization     Annual
                                                            Period      Amortization
                                                         ------------   ------------
Estimated Purchase Price Allocation:                             (estimated)
Fair Value of net tangible assets acquired
  at December 31, 2004 ....................   $    (84)

Intangible assets acquired:
Patents and patent license rights .........     25,069   3 - 10 years      4,129
                                              ---------

Total .....................................   $ 24,985
                                              =========
</TABLE>

         Management's preliminary valuation results in an estimated fair value
of patent related assets acquired of approximately $27,500,000, resulting in
approximately $2,515,000 of excess fair value over the cost of net assets
acquired, which has been allocated as a pro rata reduction to the amounts that
otherwise would have been assigned to the assets acquired, in accordance with
the purchase method of accounting.

         Management is primarily responsible for determining the fair value of
the tangible and identifiable intangible assets acquired and liabilities assumed
at the date of acquisition. Management is considering a number of factors,
including reference to an independent valuation, which is not yet complete. The
preliminary purchase price allocation is subject to revision as more detailed
analysis is completed and additional information on the fair values of the
assets and liabilities acquired becomes available. Management is in the process
of finalizing its estimates and assumptions underlying its patent related
discounted cash flow analysis and its consideration of the economic useful lives
of the amortizable intangible assets acquired. Any change in the estimated fair
value of the net assets acquired will change the amount of the purchase price
allocable to tangible and intangible assets acquired and to goodwill, if any.
Final purchase accounting adjustments may therefore differ materially from the
proforma adjustments presented here.

         The acquisition will be treated for tax purposes as a taxable asset
acquisition and, as such, Acacia Research Corporation does not expect any
book/tax basis differences and thus, no deferred income taxes will be recorded
in connection with the application of the purchase method of accounting.

3.       PRO FORMA ADJUSTMENTS

         The accompanying unaudited pro forma combined balance sheet gives
effect to the acquisition as if it had taken place on December 31, 2004. Column
(1) reflects the historical balance sheet of Global Patent Holdings, LLC as of
December 31, 2004. The unaudited pro forma combined statement of operations for
the year ended December 31, 2004, reflects the acquisition as if it had taken
place on January 1, 2004. Column (2) reflects the historical operating results
of Global Patent Holdings, LLC for the period from January 1, 2004 through
December 31, 2004. The pro forma adjustments are based upon preliminary
estimates and currently available information. Final purchase accounting
adjustments may differ from the pro forma adjustments presented.

         The Acacia Research Corporation unaudited pro forma combined statements
also give effect to the following pro forma adjustments:

         (A)      To reflect the impact on cash and cash equivalents of the
                  payment of $5,000,000 in cash on January 28, 2005,
                  representing partial consideration for the acquisition.

         (B)      To reflect the distribution of available cash and cash
                  equivalents, marketable securities and related interest
                  receivable, to Global Patent Holdings, LLC members prior to
                  the acquisition, pursuant to the terms of the legally binding
                  letter of intent between Acacia Research Corporation and
                  Global Patent Holdings, LLC, executed on December 15, 2004.

<PAGE>

         (C)      To exclude certain license fee receivables, related royalties
                  payable and related contingent legal fees payable, that were
                  not purchased or assumed by Acacia Research Corporation in the
                  acquisition, pursuant to the terms of the transaction.

         (D)      To reflect the preliminary allocation of a portion of the
                  purchase price, totaling $25,069,000, to the fair value of
                  amortizable patent related intangible assets acquired. Patent
                  related intangible assets are amortized over the estimated
                  economic useful lives of the underlying patents or patent
                  groups, ranging from 3 to 10 years.

         (E)      To accrue estimated direct acquisition costs incurred by
                  Acacia Research Corporation, totaling $480,000 and estimated
                  costs to be incurred by Acacia Research Corporation in
                  connection with the registration of the 3,938,832 shares of
                  AR-Acacia Technologies common stock issued in connection with
                  the acquisition, totaling $133,000. Acacia Research
                  Corporation executed a registration rights agreement in
                  connection with the acquisition transaction, which requires
                  Acacia Research Corporation to register for resale the shares
                  of AR-Acacia Technologies common stock issued as partial
                  consideration for the acquisition.

         (E.1)    To reflect the exclusion of certain liabilities not assumed by
                  Acacia Research Corporation in connection with the
                  acquisition, in accordance with the purchase agreement,
                  including $244,000 in benefit plan related liabilities and
                  $291,000 in accrued pension, profit sharing and management
                  bonus expenses. These liabilities are recorded at the Global
                  Patent Holdings, LLC level, and were not assumed by Acacia
                  Research Corporation in the acquisition of the 11 patent
                  licensing companies, as described above.

         (F)      To reflect the impact on stockholders equity of the issuance
                  of 3,938,832 shares of AR-Acacia Technologies common stock in
                  partial consideration for the acquisition. The value of the
                  common shares issued was determined based on the average
                  market price of AR-Acacia Technologies common stock, as
                  reported on NASDAQ, over the 5-day period before and after the
                  terms of the acquisition were agreed to and announced. The pro
                  forma adjustment also reflects a reduction in additional
                  paid-in capital related to estimated common stock registration
                  costs as described at (E ) above.

         (G)      To reflect consulting expense related to a consulting
                  agreement between Acacia Global Acquisition Corporation and
                  the former CEO of Global Patent Holdings, LLC who, as a result
                  of the acquisition, is also a shareholder of Acacia Research
                  Corporation. The consulting agreement requires the payment of
                  $2,000,000 in consulting fees over a two-year period.
                  Consulting services to be performed consist primarily of
                  consultation on intellectual property matters associated with
                  the patents and patent rights acquired in the transaction. The
                  consulting fees will be expensed as the consulting services
                  are rendered during the two-year term of the consulting
                  agreement. Acacia Global Acquisition Corporation may terminate
                  the consulting agreement for cause as provided for in the
                  agreement. The consulting agreement also contains certain
                  automatic termination provisions, including; the failure by
                  Acacia Global Acquisition Corporation to make timely
                  consulting payments in accordance with the agreement; a
                  significant decrease in working capital of Acacia Research
                  Corporation, as defined in the agreement; material breach of
                  the agreement by Acacia Global Acquisition Corporation; and
                  the death of the consultant. Any occurrence of these
                  conditions may require the payment of all remaining consulting
                  fees outstanding under the agreement within thirty days of the
                  occurrence of the termination event. Acacia Research
                  Corporation also executed an agreement guaranteeing Acacia
                  Global Acquisition Corporation's performance of its
                  obligations under the consulting agreement.

         (H)      To reflect amortization of the patent related intangible
                  assets acquired on a straight-line basis over the estimated
                  useful life of the patents or groups of patents. The estimated
                  weighted average useful life of amortizable patent related
                  intangibles is approximately 7 years.

<PAGE>

         (I)      The calculation of the pro forma weighted average Acacia
                  Research - Acacia Technologies shares outstanding was as
                  follows:

<TABLE>
<S>     <C>

                  Weighted average AR-Acacia Technologies
                    common stock outstanding for the year
                    ended December 31, 2004 (actual) ...........................    19,784,883

                  AR-Acacia Technologies common stock issued
                    in connection with the acquisition (assumed
                    issued and outstanding as of January 1, 2004) ..............     3,938,832
                                                                                   -----------

                  Pro forma weighted average AR-Acacia Technologies
                    shares outstanding for the year ended December 31, 2004 .....    23,723,715
                                                                                   ===========

</TABLE>
