The government plans to suspend its popular ôcash for clunkersö program amid concerns it could quickly use up the $1 billion in rebates for new car purchases, congressional officials said Thursday.

The Transportation Department called lawmakersÆ offices to alert them to the decision to suspend the program at midnight Friday. The program offers owners of old cars and trucks $3,500 or $4,500 toward a new, more fuel-efficient vehicle...............

Through late Wednesday, 22,782 vehicles had been purchased through the program and nearly $96 million had been spent. But dealers raised concerns about large backlogs in the processing of the deals in the government system, prompting the suspension.

A survey of 2,000 dealers by the National Automobile Dealers Association found about 25,000 deals had not yet approved by NHTSA, or nearly 13 trades per store. It raised concerns that with about 23,000 dealers taking part in the program, auto dealers may already have surpassed the 250,000 vehicle sales funded by the $1 billion program.

ôThereÆs a significant backlog of Æcash for clunkersÆ deals that make us question how much funding is still available in the program,ö said Bailey Wood, a spokesman for the dealers association. The program was scheduled to run through Oct. 31.