The city of Los Angeles opened up a $63.7 million budget deficit in the first quarter of this fiscal year -- not because of a drop in revenues but because of delays in implementing cost-cutting measures such as layoffs, according to a report released Monday.

"This deficit is attributed to the projected expenditures for civilian salary accounts, sworn (firefighters and police officers) overtime accounts, and department expense accounts based on current trends," City Administrative Officer Miguel Santana in his financial status report.

According to the report, the city is $11.3 million in the red when it comes to overtime salaries for firefighters. The corresponding shortfall for police officers is $3.8 million.

It also found the largest deficits overall are in the Police Department ($15 million), Fire Department ($13 million), General Services Department ($12 million) and City Attorney's Office ($11 million).

Santana said the city began the fiscal year with a balanced budget, but some departments did not follow the mandate to cut costs. He said the projected budget deficit for the upcoming fiscal year is $318 million -- $143 million of which represents pension costs.

Santana said that as a "last resort," about half of the shortfall could be eliminated by making a withdrawal from the city's unappropriated balance, an account containing money that has not been set aside for specific expenses.

He said the remaining gap should be closed by departments that are in a financial hole, and urged them to submit belt-tightening plans within a month.

Personnel Manager Maggie Whelan said the city already has shed about 3,500 employees in the last few years -- 2,400 through early retirement, 374 through layoffs, and 743 through transfers to proprietary departments that do not rely on the city's general fund.