Commissioning of the expansion at CTLLL

For Immediate Release

Pampa Energía Announces the Commissioning of the Combined Cycle at Central Térmica Loma de la Lata

Buenos Aires, November 1, 2011. Pampa Energía S.A. (NYSE: PAM; Buenos Aires Stock Exchange: PAMP), announces that as of 12:00 a.m. of today the Wholesale Electricity Administration Company (“CAMMESA”) granted the commissioning of Central Térmica Loma de la Lata’s (“CTLLL”) expansion works and approved it to start commercial operation in the Wholesale Electricity Market with a capacity of 165 MW. With this commissioning CTLLL’s combined cycle begins its commercial operation.

Lastly, CTLLL informs that it continues to pursue all of the appropriate claims before the insurance companies and contractors for the damages suffered due to the delays in the completion of the works and in the commissioning of the expansion, among others.

For further information, contact:

Ricardo Torres – Chief Executive Officer
Mariano Batistella – Special Projects Manager and Investor Relations Officer
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