A plan to ask Los Angeles voters to roll back retirement benefits for newly hired city workers at Los Angeles City Hall is dead - at least for now, two high-level city officials said today.

Mayor Antonio Villaraigosa's deputy chief of staff said this morning that pension benefits are spiraling out of control. But he also warned that any effort to put a measure on the June 8 ballot would be risky and have no guarantee of passage.

"This is not the time to panic," Matt Szabo told a group of reporters. "This is not the time to wildly throw up ideas onto the wall. It's time to have a reasonable, calm, strategic approach."

City Administrative Officer Miguel Santana floated the idea of a June ballot measure earlier this month, saying the city's retirement system is "unsustainable" and would consume increasingly larger amounts of taxpayer dollars unless changes are made.

Santana began examining the idea, at least for public safety employees, on the orders of the city's negotiating committee - a panel that includes Villaraigosa.

Budget analysts expect taxpayers' share of the city pension costs to jump from $653 million this year to nearly $1.3 billion by 2013 for every agency but the Department of Water and Power, which has a separate retirement system.

Szabo and a representative of City Council President Eric Garcetti said they believe they can achieve savings more quickly by negotiating directly with the unions that represent civilian city employees.

Although changes to retirement benefits for police officers and firefighters must go to the ballot, similar changes for civilian employees can be made by a vote of the council.

"The mayor's intent is to map out the best route to successfully implement pension reform," Szabo said. "A rush to throw something on the June ballot is not in anyone's interests."