Unassociated Document

Chief Financial Officer and Affiliated Companies

Petersen Energía Inversora, S.A.U.

c/o Velázquez 9, Planta 1

28006 Madrid

Spain

Attn: Ignacio Moran and Mauro Dacomo

Facsimile: + 54 11 5 555 0162

With a copy to:

Cerrito 740, Piso 1

C1010AAP, Buenos Aires

Argentina

c.c.:

The Bank of New York Mellon

Corporate Trust Global Americas

101 Barclay Street 4E

New York, NY 10286

Attn: Erika C. Walker

Facsimile: +1 (212) 815-5390

With a copy to (which shall not constitute notice):

Emmet, Marvin & Martin, LLP

120 Broadway 32nd Floor

New York, NY 10271

Facsimile: +1 (212) 238-3100

Attn: Margery A. Colloff

Madrid, May 30, 2012

Re: Pledge and Security Agreement dated as of May 19, 2011 (“the Pledge Agreement”) between Petersen Energía Inversora, S.A.O (“PEISA”) and The Bank of New York Mellon (“BoNY”).

Ladies and Gentlemen,

Reference is made to the Pledge Agreement.

In particular, reference is made to section 4.04(b) and section 4.05(a) of the Pledge Agreement.

Unless otherwise defined in this letter, defined terms used in this letter shall have the meaning assigned to them in the Pledge Agreement.

Pursuant to the terms of the Seller Credit Agreement, on May 30, 2012, Seller notified PEISA the occurrence of certain Events of Default and the acceleration of the Seller Credit Agreement.

By this letter, we request your confirmation in respect to the following facts (i) pursuant to section 4.04(b) of the Pledge Agreement, PE1SA ceased to be entitled to exercise the voting, consensual and other powers of ownership pertaining to the Pledged Shares as of the occurrence of the Events of Default; and (ii) pursuant to section 4.05(a) of the Pledge Agreement, BoNY has the right to exercise the voting, consensual and other powers of ownership pertaining to the Pledged Shares pursuant to the instructions provided by the Seller.

Should you agree with the facts set out above, please sign the enclosed copy of this letter acknowledging and accepting them and return it to us.

Sincerely,

/s/ Miguel Martinez San Martín
Mr. Miguel Martinez San Martín

Title: Chief Executive Officer

Repsol YPF, S.A.

Acknowledged and accepted:

/s/ Mauro Dacomo

Mr. Mauro Dacomo

Petersen Energia lnversora, S.A.U.

Chief Financial Officer and Affiliated Companies

Petersen Energia, S.A.

c/o Grupo Petersen

Cerrito 740, Piso 1

(C1010AAP) Buenos Aires Argentina

Attn: Mauro Dacomo

Facsimile: + 54 11 45 555 0162

c.c.

The Bank of New York

Global Trust Services

101 Barclay Street 4E

New York, NY 10286

Facsimile: +1 (212) 815-5802

Madrid, May 30, 2012

Re Pledge and Security Agreement dated as of February 21, 2008 (“the Pledge Agreement”) between Petersen Energia, SA (“PESA”) and The Bank of New York (“BoNY”).

Ladies and Gentlemen,

Reference is made to the Pledge Agreement.

In particular, reference is made to section 4.04(b) and section 4.05(a) of the Pledge Agreement.

Unless otherwise defined in this letter, defined terms used in this letter shall have the meaning assigned to them in the Pledge Agreement.

Pursuant to the terms of the Seller Credit Agreement, on May 30, 2012, Seller notified PESA the occurrence of certain Events of Default and the acceleration of the Seller Credit Agreement.

By this letter, we request your confirmation in respect to the following facts (i) pursuant to section 4.04(b) of the Pledge Agreement, PESA ceased to be entitled to exercise the voting, consensual and other powers of ownership pertaining to the Pledged Shares as of the occurrence of the Events of Default; and (ii) pursuant to section 4.05(a) of the Pledge Agreement, BoNY has the right to exercise the voting, consensual and other powers of ownership pertaining to the Pledged Shares pursuant to the instructions provided by the Seller.

Should you agree with the facts set out above, please sign the enclosed copy of this letter acknowledging and accepting them and return it to us.

Sincerely,

/s/ Miguel Martinez San Martín
Mr. Miguel Martinez San Martín

Title: Chief Executive Officer

Repsol YPF, S.A.

Acknowledged and accepted:

/s/ Mauro Dacomo

Mr. Mauro Dacomo

Petersen Energia, S.A.