Los Angeles union leaders urged city officials Wednesday to crack down on fraud and abuse in the pension system instead of resorting to a proposed ballot measure that would scale back pension payments for future city employees.

"We agree wholeheartedly that pensions do need to be reformed," said Barbara Maynard, a spokeswoman for the 22,000-member Coalition of L.A. City Unions.

"There's a tremendous amount of fraud and abuse of the pension system: people double dipping, people retiring with pensions in excess of $100,000," she said.

"We do not agree that pensions for basic city workers - which are on average $35,000 a year - we do not think those pensions should be cut. These are workers who are not in the Social Security system and they do not have any other form of retirement income."

Earlier Wednesday, City Administrative Officer Miguel Santana briefed the City Council behind closed doors about a range of proposals to reduce the city's pension costs, including a June 8 ballot measure that would significantly reduce payments for workers who are hired in the future.

The city's three pension funds - one for civilian workers, a second for police and firefighters, and a third for employees of the Department of Water and Power - have been reeling from investment losses because of the economic recession.

Under the city charter, when the pension funds cannot meet payments to retirees, taxpayers must compensate for the shortfall. Santana, the city's top budget analyst, projected taxpayers will spend $300 million on pensions this fiscal year and about $550 million in 2013-14.

"The options we're exploring are those that bring us to a point of sustainability where our pension system is sustainable and fair and keeps us competitive in the work force," he said.

But Maynard said the proposals would deal a devastating blow to retirees.

"Let me make something very clear: if for whatever reason they continue to push an agenda that cuts workers' pensions that average $35,000 a year, which would effectively bankrupt retirees, it is something that we will absolutely fight," she said.

Maynard instead urged officials to stop the practice of "double dipping" - people retiring on a pension and then going back to work for the city and drawing a salary - and putting a cap on pension payments.

As of last year, the city had about 600 retirees collecting an annual pension of more than $100,000.

City Council President Eric Garcetti said he and his colleagues were considering every option on the table, including the ballot measure.

"People recognize that while pension reform might not balance the budget in the short term, it will be an important investment in the city's future," he said. "The question is how can we do this responsibly in a way that rewards our workers but doesn't bankrupt our cities?"

Mayor Antonio Villaraigosa said he has yet to take a position on the issue, but added, "I can tell you this: that we have an unfunded liability with our pension and we're going to have to do something very seriously different from what we've done in the past with respect to reducing the unfunded liability."

The City Council must decide by Feb. 3 whether to pursue a ballot measure to shrink pension payments for one, two or all three groups of city employees in the June 8 election.

Most city employees currently contribute 6 percent of their salaries toward their pension. Late last year, they agreed to increase that amount to 7 percent to fund the early retirement of 2,400 colleagues and avert layoffs.

The official said proposed changes in the retirement plan will call for an even larger contribution - but would affect only new hires, not current employees.

Any changes to the pension plan for fire and police employees would require a charter amendment, but not so for the city's civilian employees, including those at the LADWP.

Nevertheless, Santana said he plans to meet with union leaders over the coming days "to try to reach common ground."