UPDATE 2-Mexican pension bill passes Congress hurdle

(Adds vote likely Thursday)

MEXICO CITY, March 20 (Reuters) - A proposal to overhaul Mexico's government pension system easily cleared congressional committees on Tuesday, fueling optimism for President Felipe Calderon's economic reform agenda.

Calderon's conservative National Action Party, or PAN, and three other parties approved a bill in two lower-house committees.

The legislation, which would introduce private retirement accounts for public-sector workers, now looks likely to be voted on by deputies of the lower chamber of Congress on Thursday. It would then be voted on in the Senate.

The measure appears to stand a good chance of passing thanks to backing from the Institutional Revolutionary Party, or PRI, which is Mexico's third-largest party.

Together, the PAN and the PRI form a majority, and Calderon called on lawmakers to approve the measure.

"I hope Congress votes responsibly," he said.

The bill won unanimous approval in a predawn vote on the committees, though members of the leftist Party of the Democratic Revolution, or PRD, boycotted the vote.

The PRD lacks the votes to block the measure and local media reported that hundreds of leftists protested outside of Congress, with some vandalizing cars with paint.

Investors have closely followed the negotiations in Congress because ballooning retirement obligations for state workers are expected to fuel ever-larger budget deficits in coming years.

Also, the alliance between the PAN and the PRI, if it holds, is seen as a good sign for the Calderon's hopes of pushing through fiscal, labor and energy reforms to make Mexico more competitive. Congress blocked similar reforms proposed by his predecessor, Vicente Fox.

Mexico's public-sector work force is aging, and pension contributions by new workers are not keeping up with obligations owed to new retirees.

Calderon's government has warned that unless Congress tackles the problem this year, the government could run a budget deficit equivalent to 3.0 percent of gross domestic product by 2012.

The government ran a small surplus in 2006 and has a balanced budget for 2007.

Economists say the bill would initially push the government to take on extra debt, but would bolster public finances in the long term.