UPDATE 1-Pemex eyes full oil reserves replacement in 2012

(Recasts, updates with further comments from Morales, adds details about plans)

MEXICO CITY, March 26 (Reuters) - Mexican state-owned oil monopoly Pemex still aims to lift its oil and gas reserves replacement rate to the industry ideal of 100 percent in 2012, a company official said on Wednesday .

Exploration and Production Director Carlos Morales said confirmation of new discoveries would help Pemex stem a steady decline in reserves since 1999. He said the 100 percent replacement goal applied to proved and total reserves alike.

To meet the target, Pemex must double the rate at which it replaces extracted oil with new discoveries. That goal is broadly in line with progress it has made improving ratios since the start of the decade.

Pemex's replacement rate for proved reserves, known as 1P, was 50.3 percent at the end of 2007 -- meaning one new barrel of oil is discovered for every two extracted. That is up from 41 percent a year earlier and 26.4 percent at the end of 2005.

For total, or 3P, reserves, Pemex's replacement ratio was 65.7 percent at end-2007, up from 59.7 percent a year earlier.

"In the following years there will be reclassifications of our reserves into proved reserves primarily due to the development of the projects Ku Maloob Zapp, Crudo Lijero Marina and Chicontepec," Morales told an investor conference call.

Pemex is under pressure to speed up exploration of deepwater oil deposits where preliminary seismic tests indicate there could be some 30 billion barrels of oil. But the company says progress will be slow unless the law is changed to allow it to partner with experienced foreign oil majors.

Mexican lawmakers are debating a reform of the energy sector which the ruling conservatives want to lower barriers to private joint ventures in the state-run oil sector, but left-wingers strongly oppose the idea. (Reporting by Catherine Bremer; Editing by David Gregorio)