Closing of Acquisition of Certain AEI Distribution Assets

For Immediate Release

Pampa Energía announces the closing of the acquisition of certain distribution assets from AEI

Buenos Aires, March 4, 2011. Pampa Energía S.A. (NYSE: PAM; Buenos Aires Stock Exchange: PAMP) (“Pampa” or the “Company”) informs that today Empresa Distribuidora y Comercializadora Norte S.A. (“Edenor”) accepted an offer for no consideration from Pampa to designate Edenor as the buyer under certain agreements entered into by Pampa with a group of subsidiaries of AEI (the “Sellers”) – agreements that were informed at the appropriate time through a relevant event notice on January 19, 2011 – pursuant to which Edenor, a subsidiary of Pampa, would directly acquire: 99.99% of the equity and votes of AESEBA S.A. (“AESEBA”), the holding company of 90% of the equity and votes of Empresa Distribuidora de Energía Norte S.A., an electricity distributor with a concession area in the north and center of the province of Buenos Aires; and 77.2% of the equity and votes of Empresa Distribuidora Eléctrica Regional S.A. (“EMDERSA”). EMDERSA is the controlling company of Empresa Distribuidora San Luis S.A., Empresa Distribuidora de Electricidad de la Rioja S.A., and Empresa Distribuidora de Electricidad de Salta S.A. , among others. As a consequence of the aforementioned, Edenor acquired the right to purchase the shareholdings referred to previously for a total price of US$ 139,998,283 of which US$ 49,998,283 corresponds to the acquisition of the shares of AESEBA and US$ 90,000,000 to the acquisition of the shares of EMDERSA. Within the referred offer the Company and Edenor also agreed that the Company would directly acquire 0.01% of the shares of AESEBA – for an amount of US$ 1,717 – and, additionally, that in the event that within 3 years following the date of acquisition of the shares of EMDERSA and the shares of AESEBA Edenor would partially or completely sell any of said shares, Pampa will have the right to receive from Edenor a payment equivalent to 50% of the value received by Edenor in excess of what it paid to the Sellers for the shares of EMDERSA and/or the shares of AESEBA that it may be selling. The acquisition of said shareholdings by the Company and Edenor has been executed today. Edenor’s Audit Committee has opined that the transaction was done at normal and usual market terms.

Lastly, we inform that the obligation to conduct a public tender offer due to change of control of EMDERSA pursuant to the terms of Decree 677/01 and the Norms of the Argentine Securities Commission has been assumed by Edenor, company that will carry it out in the way, form and timing that is finally determined, in accordance with the consultation that Pampa posed to the Argentine Securities Commission, due to the pending execution of a similar public tender offer by AEIU as a result of a pre-existing change of control at EMDERSA, in which the Argentine Securities Commission has requested further clarifications from the Company today, and which terms have been informed to Edenor.

Pampa Energía is the largest integrated electricity company in Argentina that, through its subsidiaries, participates in the generation, transmission and distribution of electricity.

For further information, contact:

Ricardo Torres – Chief Executive Officer
Mariano Batistella – Strategic Planning and Investor Relations
3302 Ortiz de Ocampo, Building #4
(C1425DSR) Ciudad Autónoma de Buenos Aires, Argentina
Phone: 5411 4809 9500
http://www.pampaenergia.com/ir
investor@pampaenergia.com