Modification of the Merger Exchange Ratio

Buenos Aires, December 23, 2016. Pampa Energía S.A. (‘Pampa‘ or the ‘Company‘; NYSE: PAM; BCBA: PAMP) informs that, as we disclosed to the market on December 19, 2016, the Argentine National Securities Commission (‘Comisión Nacional de Valores‘ or the ‘CNV‘) informed Pampa of its decision to reject the proposed exchange ratio between Pampa, as the surviving company, and Petrobras Argentina S.A. (‘Petrobras Argentina‘), Petrobras Energía Internacional S.A. (‘PEISA‘) and Albares Renovables Argentina S.A. (‘Albares‘), as the absorbed companies. In accordance with the notice from the CNV, the CNV understands that there are no objective changes in the economic circumstances involving the companies for which reason the exchange ratio offered in the voluntary exchange offer that expired on November 14, 2016 should be changed.

Along these lines, Pampa and Petrobras Argentina have analyzed the consequences of appealing such decision and believe that it would result in serious delays to the merger process, and Pampa and Petrobras Argentina have resolved to accept the request from the CNV, thereby modifying the merger exchange ratio and fixing it at the same ratio that was used in the voluntary exchange offer, which was 0.5253 ordinary shares of Pampa, with a par value of AR$1 and one vote per share, for each ordinary Class B share of Petrobras Argentina, with a par value of AR$1 and one vote per share.

For further information, contact:

Gustavo Mariani – Vice-President and Co-Chief Executive Officer
Ricardo Torres – Vice-President and Co-Chief Executive Officer
Mariano Batistella -Planning, Strategy and Affiliates Executive Director
Lida Wang – Investor Relations Officer

Maipú 1, (C1084ABA), Buenos Aires, Argentina
Phone: +54 (11) 4344 6000
http://www.pampaenergia.com/ir
investor@pampaenergia.com