UNITED STATES
 SECURITIES AND EXCHANGE COMMISSION
 WASHINGTON, D.C. 20549


FORM 20-F/A


Amendment No. 1




o
REGISTRATION STATEMENT PURSUANT TO SECTION 12(b) OR (g)

OF THE SECURITIES EXCHANGE ACT OF 1934


OR


x
ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d)

OF THE SECURITIES EXCHANGE ACT OF 1934

For the fiscal year ended December 31, 2009
 OR
 o
TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE

SECURITIES EXCHANGE ACT OF 1934


OR
 o
SHELL COMPANY REPORT PURSUANT TO SECTION 13 OR 15(d)

OF THE SECURITIES EXCHANGE ACT OF 1934


Date of event requiring this shell company report





For the transition period from            to





Commission file number 001-14370





COMPAÑÍA DE MINAS BUENAVENTURA S.A.A.


(Exact name of Registrant as specified in its charter)




BUENAVENTURA MINING COMPANY INC.


(Translation of Registrant’s name into English)




REPUBLIC OF PERU


(Jurisdiction of incorporation or organization)




CARLOS VILLARAN 790


SANTA CATALINA, LIMA 13, PERU


(Address of principal executive offices)




Carlos E. Gálvez, Vice President and Chief Financial Officer


Telephone: (511) 419-2540


Facsimile: (511) 471-7349


Address: Carlos Villaran 790, Santa Catalina, Lima 13, Peru


(Name, telephone, e-mail and/or facsimile number and address of company contact person)




Securities registered or to be registered pursuant to Section 12(b) of the Act:




Title of each class

Name of each exchange on which registeredCommon shares, nominal (par) value of

four Peruvian Nuevos Soles per share



American Depositary Shares (ADSs)

representing one Common share each

New York Stock Exchange Inc.٭

Lima Stock Exchange



New York Stock Exchange Inc.




٭  Not for trading but only in connection with the registration of ADSs pursuant to the requirements of the Securities Exchange Commission





Securities registered or to be registered pursuant to Section 12(g) of the Act:  None





Securities for which there is a reporting obligation pursuant to Section 15(d) of the Act:  None










Indicate the number of outstanding shares of each of the issuer’s classes of capital or common stock as of the close of the period covered by the annual report.




Common shares nominal (par) value of S/.10.00 per share
274,889,924*Investment shares nominal (par) value of S/.10.00 per share
744,640




Indicate by check mark if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act.




Yes x      No  ̈





If this report is an annual or transition report, indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934.




Yes  ̈      No x





Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days.




Yes x      No  ̈





Indicate by check mark whether the registrant has submitted electronically and posted on its corporate Web site, if any, every Interactive Data File required to be submitted and posted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit and post such files).




Yes  ̈      No  ̈




Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, or a non-accelerated filer.  See definition of “accelerated filer and large accelerated filer” in Rule 12b-2 of the Exchange Act.




Large accelerated filer x      Accelerated filer  ̈      Non-accelerated filer  ̈





Indicate by check mark which basis of accounting the registrant has used to prepare the financial statements included in this filing:




U.S. GAAP   ̈
International Financial Reporting Standards as issued

by the International Accounting Standards Board   ̈
Other x




If “Other” has been checked in response to the previous question, indicate by check mark which financial statement item the registrant has elected to follow.




Item 17  ̈      Item 18 x




If this is an annual report, indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act).


Yes  ̈      No x










EXPLANATORY NOTE





We are filing this Amendment No. 1 to our Annual Report on Form 20-F for the fiscal year ended December 31, 2009 originally filed with the Securities and Exchange Commission on June 11, 2010 (the “Original 2009 Form 20-F”) to correct an administrative error in the presentation of notes 33 and 34 to the audited financial statements of Compañía de Minas Buenaventura S.A.A. and its consolidated subsidiaries (the “Company”) included in the Original 2009 Form 20-F.  We hereby replace notes 33 and 34 to the Company’s consolidated financial statements on pages F-67 to F-73 of the Original 2009 Form 20-F in their entirety with the corrected notes 33 and 34 included in this Amendment No. 1.





We are including in this Amendment No. 1 currently-dated certifications by our principal executive officer and our principal financial officer. Other than as expressly set forth above, this Amendment No. 1 does not, and does not purport to, amend, update or restate the information in any other item of the Original 2009 Form 20-F, or reflect any events that have occurred after the Original 2009 Form 20-F was originally filed.









PART III




ITEM 19.           Exhibits




The exhibits listed on the Exhibit Index hereof are filed herewith in response to this Item.




Page(a) Index to Financial Statements and SchedulesCOMPAÑIA DE MINAS BUENAVENTURA S.A.A. AND SUBSIDIARIESNotes 33 and 34 to the consolidated financial statements

F-1(b) Index to Exhibits12.1
Certification of Chief Executive Officer of Compañía de Minas Buenaventura S.A.A.

pursuant to Section 302 of the Sarbanes-Oxley Act of 2002.12.2
Certification of Chief Financial Officer of Compañía de Minas Buenaventura S.A.A.

pursuant to Section 302 of the Sarbanes-Oxley Act of 2002.13.1
Certification of Chief Executive Officer of Compañía de Minas Buenaventura S.A.A.

pursuant to Section 906 of the Sarbanes-Oxley Act of 2002.13.2
Certification of Chief Financial Officer of Compañía de Minas Buenaventura S.A.A.

pursuant to Section 906 of the Sarbanes-Oxley Act of 2002.











SIGNATURE




The registrant hereby certifies that it meets all of the requirements for filing on Form 20-F/A and that it has duly caused and authorized the undersigned to sign this annual report on its behalf.




COMPAÑÍA DE MINAS BUENAVENTURA S.A.A.By:
/S/ CARLOS E. GÁLVEZ PINILLOSCarlos E. Gálvez PinillosChief Financial Officer




Dated:  May 27, 2011









Notes 33 and 34 to the Company’s Consolidated Financial Statements




33.
Summary of significant differences between accounting principles followed by the Company and U.S. generally accepted accounting principles





Differences in preparation





The Company's consolidated financial statements have been prepared in accordance with Peruvian GAAP which differs in certain respects from U.S. GAAP.  The effects of these differences are reflected in Note 34 and are principally related to the items discussed in the following paragraphs:





Shares in Yanacocha and Cerro Verde


Peruvian GAAP – In the consolidated financial statements, Yanacocha and Cerro Verde are accounted for by the equity method.  The consolidated results and shareholders’ equity include the participation in Yanacocha and Cerro Verde which are obtained from their financial statements prepared following Peruvian GAAP, modified to recognize the current accounting policies of Buenaventura.





U.S. GAAP – The consolidated results and shareholders’ equity under U.S. GAAP include the shares in Yanacocha and Cerro Verde obtained from those entities financial statements prepared in accordance with U.S. GAAP.





Deferred Income Tax


Peruvian GAAP – Under paragraph 70 of IAS 1, Presentation of Financial Statements, deferred tax assets and liabilities are always classified as non-current assets or liabilities.





U.S.GAAP – Deferred income tax liabilities and assets shall be classified as current or non-current based on the classification of the related asset or liability for financial reporting purposes.





Under Peruvian GAAP, IAS 12 – Income Taxes, the Company must consider the effect on the deferred income tax and workers’ profit sharing generated by maintaining book basis in U.S. dollars and a tax basis in Nuevos Soles (for tax purposes, the functional currency is Nuevos Soles).  US GAAP, ASC 740 Income Taxes (FAS 109 Accounting for Income Taxes), prohibits the recognition of a deferred tax liability or asset for differences related to non-monetary assets and liabilities that, under ASC 830 Foreign Currency Translation (FAS 52), are remeasured from the local currency into the functional currency using historical exchange rates and that result from changes in exchange rates.  Therefore, the deferred income tax recorded under Peruvian GAAP has been included as a reconciliation item, see note 34.




F-1





Workers' profit sharing


Peruvian GAAP – Workers' profit sharing expense (income) is separately presented in the consolidated statements of income in a similar way as income tax expense (income).  Also, deferred workers' profit sharing asset (liability) is separately presented in the consolidated balance sheets in a similar way as deferred income tax assets (liabilities).





U.S. GAAP – The practice is to recognize the workers' profit sharing expense (income) as part of operating expense (income).  Also, deferred workers' profit sharing assets (liabilities) shall be classified as current or non-current based on the classification of the related assets or liability for financial reporting purposes.





See also discussion on recognition of deferred tax liability or asset arising from remeasurement from the local currency into the functional currency in the section Deferred Income Tax above.




Equity accounts translation


Peruvian GAAP – Under Peruvian GAAP, based on IAS 21 - The Effects of Changes in Foreign Exchange Rates, when there is a change in an entity’s functional currency,the entity shall apply the translation procedures applicable to the new functional currency prospectively from the date of the changeusing the exchange rate at the date of the change.  The resulting translated amounts for non-monetary items are treated as their historical cost.  Therefore, for Peruvian GAAP purposes, the Company has translated equity accounts into U.S. dollars using the exchange rate as of December 31, 2005 when it changed its functional currency from Peruvian Soles to U.S. dollars.





U.S. GAAP – Under U.S. GAAP, based on ASC 830 Foreign Currency Translation (codified mainly from FAS 52), equity accounts should be translated into U.S. dollars using historical exchange rates.  The cumulative translation loss amounts to US$19,323,000 (US GAAP) and US$34,075,000 (Peru GAAP) as of December 31, 2009 and 2008.  It has no effect on total equity as of December 31, 2009 and 2008.





Impairment of long-term assets


Peruvian GAAP – Under Peruvian GAAP, based on IAS 36 – Impairment loss is calculated by comparing the net carrying amount of the asset to its recoverable amount, which is the higher of its value in use or fair value less costs to sell.  Under IAS 36 the provision amounted US$3,325,000 for the year ended December 31, 2009.





U.S. GAAP – Under U.S. GAAP, ASC 360 Accounting for the impairment or disposal of long-lived assets (FAS 144), Impairment is considered to exist if total estimated undiscounted  cash flows are less than the carrying amount of the asset and an impairment loss is then measured as the amount by which the carrying value of the asset exceeds its fair value.  Once recognized, an impairment loss is not reversed.  Under ASC 360 the provision amounted US$2,086,000 as of December 31, 2009.




F-2





Provision for closure of mining units and exploration projects


Peruvian GAAP – Under Peruvian GAAP, based on IFRIC 1 and IAS 37 – Provisions are adjusted at each balance sheet date to reflect the current best estimate. If the provision was discounted, the provision should increase in each period to reflect the passage of time. The interest rate used to measure that change is pre-tax rate that reflects current market assessments of the time value of money and the risks specific to the liability as of each consolidated balance sheet date. Under Peruvian GAAP, the accretion expense amounted US$4,839,000 for the year ended December 31, 2009.





U.S. GAAP – Under U.S. GAAP, FAS 143 “Accounting for Asset Retirement Obligation (subsequently codified within ASC 410 Asset Retirement and Environmental Obligations), changes to an ARO due to the passage of time are measured by applying an interest method of accretion to the amount of the liability at the beginning of the period. The interest rate used to measure that change is the credit-adjusted riskfree rate that existed when the liability, or portion thereof, was initially measured. That change is recognized as an increase in the carrying amount of the ARO and as accretion expense (not interest).  Under US GAAP the accretion expense amounted US$6,946,000 as of December 31, 2009.





Differences in presentation


Presentation of royalties and unusual item related to net loss from release of commitments in commercial contracts





Peruvian GAAP – Royalties granted to the Peruvian State and third parties amounting to US$39,646,000, US$35,694,000 and US$33,978,000 in 2009, 2008 and 2007, respectively, as well as the unusual item related to net loss from release of commitments in commercial contracts amounting to US$415,135,000 and US$185,922,000 in 2008 and 2007, respectively, are presented as part of operating expenses.





US GAAP – The royalties above mentioned must be presented as part of operating costs, affecting the gross margin.  The presentation of the loss on the derivative contracts as unusual item is not permitted.





34.
Reconciliation between net income and shareholders' equity determined under Peruvian GAAP and U.S. GAAP


Until December 31, 2005, the Company had designated Peruvian Nuevos Soles as its functional and reporting currency.  Effective January 1, 2006, the functional and reporting currency of the Company is U.S. dollar for Peruvian GAAP and U.S. GAAP purposes.  The methodology of translation from Nuevos Soles into U.S. dollars and the reasons supporting this change are described in note 2.2 (a) of the consolidated financial statements.  The reconciliation tables below show only the reconciliation of net income and shareholders’s equity attributable to Buenaventura because there are no differences between Peruvian GAAP and U.S.  GAAP that affect the minority interests.




F-3





The following is a summary of the adjustments to net income for the years ended December 31, 2009, 2008 and 2007 and to shareholders' equity as of December 31, 2009 and 2008 that would be required if U.S. GAAP had been applied instead of Peruvian GAAP in the consolidated financial statements:





2009


2008


2007US$(000)


US$(000)


US$(000)Net Income attributable to Buenaventura, under Peruvian GAAP


593,561



153,283



274,761Items increasing (decreasing) reported net incomeProvision for impairment of long-term assets


1,239



2,767



-Other


32



32



32Share in investment in affiliate


-



(1,301
)


(44,356
)Deferred Income tax and workers ́ profit sharing arising from having a functional currency different from the currency used for tax purposes


(4,801
)


6,385



(4,968
)Accretion expense of the provision for closure of mining units


(2,107
)


-



-Deferred Income tax and workers’ profit sharing assets, net


(452
)


(996
)


(11
)Net adjustments


(6,089
)


6,887



(49,303
)Net income attributable to Buenaventura, under U.S. GAAP


587,472



160,170



225,458Other comprehensive income (loss)Unrealized gain (loss) on other investments


557



(40
)


61Financial Investments maintained at fair value


-



-



798Realization of accumulated gain on financial instruments available-for-sale


-



-



(1,633
)Unrealized gain (loss) on valuation of hedge derivate financial instruments, net


(20,753
)


14,644



1,518Total comprehensive income under U.S. GAAP attributable to Buenaventura


567,276



174,774



226,202





F-4




Accumulated other comprehensive income (loss) under U.S. GAAP attributable to BuenaventuraUnrealized gain (loss) on other investments


675



118



158Cumulative translation loss


(34,075
)


(34,075
)


(34,075
)Unrealized gain (loss) on valuation of hedge derivate financial instruments, net


(4,591
)


16,162



1,518Total accumulated other comprehensive loss under U.S. GAAP attributable to Buenaventura


(37,991
)


(17,795
)


(32,399
)Basic and diluted income per share under U.S. GAAP attributable to Buenaventura


2.31



0.63



0.89




2009


2008


2007US$(000)


US$(000)


US$(000)Shareholders ́ equity attributable to Buenaventura, according to the financial statements under Peruvian GAAP


2,064,255



1,531,601



1,414,602Items increasing (decreasing) reported shareholder ́s equityShare in investment in affiliate


(45,657
)


(45,657
)


(44,356
)Deferred income tax and worker's profit sharing arising from having a functional currency different from the currency used for tax purposes


(5,920
)


(1,119
)


(8,923
)Accretion expense of the provision for closure of mining units


(2,107
)


-



-Provision for impairment of long-term assets, net


336



1,287



(527
)Other


165



176



188Shareholders ́ equity attributable to Buenaventura, according to the financial statements under U.S. GAAP


2,011,072



1,486,288



1,360,984




F-5




The following is a roll forward of the components of shareholders' equity  attributable  to Buenaventura under U.S. GAAP:





US$(000)Shareholders ́ equity attributable to Buenaventura, under U.S. GAAP at January 1, 2007


1,205,328Net Income in accordance with U.S. GAAP


225,458Declared and paid dividends


(69,972
)Financial Investments held at fair value


(835
)Unrealized gain on other investments


61Unrealized gain on valuation of hedge derivate financial instruments, net


1,518Other


(574
)Shareholders ́ equity attributable to Buenaventura, under U.S. GAAP at December 31, 2007


1,360,984Net Income in accordance with U.S. GAAP


160,170Declared and paid dividends


(50,888
)Unrealized loss on other investments


(40
)Unrealized gain on valuation of hedge derivate financial instruments, net


14,644Other


1,418Shareholders ́ equity attributable to Buenaventura, under U.S. GAAP at December 31, 2008


1,486,288Net Income in accordance with U.S. GAAP


587,472Declared and paid dividends


(40,711
)Unrealized gain on other investments


557Unrealized loss on valuation of hedge derivate financial instruments, net


(20,753
)Other


(1,781
)Shareholders ́ equity attributable to Buenaventura, under U.S. GAAP at December 31, 2009


2,011,072





Recently adopted accounting pronouncements:





The Accounting Standards Codification -


In June 2009, the Financial Accounting Standards Board (“FASB”) established the FASB Accounting  Standards Codification (“ASC”) as the single source of authoritative generally accepted accounting principles (“GAAP”) to be applied by nongovernmental entities. The ASC is a new structure which took existing accounting pronouncements and organized them by accounting topic. Relevant authoritative literature issued by the Securities and Exchange Commission (“SEC”) and select SEC staff interpretations and administrative literature was also included in the ASC. All other accounting guidance not included in the ASC is non-authoritative. The ASC was effective for interim quarterly periods beginning July 1, 2009. The adoption of the ASC did not result in a change in the Company ́s accounting principles.





F-6




Noncontrolling Interests in Consolidated Financial Statements -


In December 2007, FAS 160: Noncontrolling Interests in Consolidated Financial Statements an amendment of ARB No. 51 (subsequently codified within ASC 810 Consolidation) was issued in order to  establish accounting and reporting standards pertaining to ownership interests in subsidiaries held by parties other than the parent, the amount of net income attributable to the parent and to the no controlling interest, changes in a parent’s ownership interest, and the valuation of any retained no controlling equity investment when a subsidiary is deconsolidated.  ASC 810 also establishes disclosure requirements that clearly identify and distinguish between the interests of the parent and the interests of the no controlling owners.  ASC 810 is effective for the Company’s fiscal year beginning January 1, 2009 with early adoption prohibited.  This statement is required to be adopted prospectively, except for the following provisions, which are expected to be applied retrospectively: (i) the reclassification of noncontrolling interests to equity in the consolidated balance sheets and (ii) the adjustment to consolidated net income to include net income attributable to both the controlling and noncontrolling interests.  The Company has complied with such requirements.





The Company adopted the updated guidance on January 1, 2009. Except for presentation changes related to noncontrolling interest classified as a component of equity, the adoption had no impact on the Company ́s consolidated financial position and results of operations or cash flows.





Business Combinations -


In December 2007, FAS 141 (R) “Business Combination” (subsequently codified within ASC 805) was issued in order to provide revised guidance for recognizing and measuring identifiable assets and goodwill acquired, liabilities assumed, and any non controlling interest in the acquiree.  It also provides disclosure requirements to enable users of the financial statements to evaluate the nature and financial effects of the business combination.  ASC 805 is effective for business combinations for which the acquisition date is January 1, 2009 or later and is to be applied prospectively.  Early adoption is prohibited.  The adoption of ASC 805 will have on impact on the Company ́s financial statements depending on whether the Company enters into business combination transaction in the future.





Equity Method Investments -


In November 2008, EITF 08-6 (subsequently codified within ASC 323) the guidance for equity method and joint venture investments was updated to clarify the accounting for certain transactions and impairment considerations involving equity method investments. The intent is to provide guidance on: (i) determining the initial measurement of an equity method investment, (ii) recognizing other-than-temporary impairments of an equity method investment and (iii) accounting for an equity method investee’s issuance of shares. The updated guidance is effective for the Company’s fiscal year beginning January 1, 2009 and should be applied prospectively. The adoption had no impact on the Company’s consolidated financial position or results of operations.





F-7





Subsequent Events -


In May 2009, the guidance for subsequent events was updated to establish accounting and reporting standards for events that occur after the balance sheet date but before financial statements are issued or are available to be issued. The update sets forth: (i) the period after the balance sheet date during which management of a reporting entity should evaluate events or transactions that may occur for potential recognition or disclosure in the financial statements, (ii) the circumstances under which an entity should recognize events or transactions occurring after the balance sheet in its financial statements, and (iii) the disclosures that an entity should make about events or transactions occurring after the balance sheet date in its financial statements. This ASC guidance is effective for the Company’s interim period beginning June 30, 2009. The adoption of this pronouncement and related amendments had no impact on the Company’s consolidated financial position, results of operations or cash flows.




F-8




Exhibit Index




Exhibit No.

Document Description12.1

Certification of Chief Executive Officer of Compañía de Minas Buenaventura S.A.A. pursuant to Section 302 of the Sarbanes-Oxley Act of 2002. †12.2

Certification of Chief Financial Officer of Compañía de Minas Buenaventura S.A.A. pursuant to Section 302 of the Sarbanes-Oxley Act of 2002. †13.1

Certification of Chief Executive Officer of Compañía de Minas Buenaventura S.A.A. pursuant to Section 906 of the Sarbanes-Oxley Act of 2002. †13.2

Certification of Chief Financial Officer of Compañía de Minas Buenaventura S.A.A. pursuant to Section 906 of the Sarbanes-Oxley Act of 2002. †





† Filed herewith.