General Motors Corp. is likely to announce further production cuts and possible plant closures as early as next week as it deals with slumping sales and a collapse in its stock price, a person with knowledge of the company's plans said Friday.

The person, who did not want to be identified because the plans are not finalized, said the cuts likely will hit engine, transmission and stamping operations to correspond with a June announcement that GM would close four truck and sport utility vehicle assembly plants.

The closures of those assembly plants likely will be accelerated, the person said. GM announced last week that its Moraine, Ohio, SUV factory will close Dec. 23, and it has said it will idle assembly factories in Oshawa, Ontario; Toluca, Mexico; and Janesville, Wis., by 2010.

Chairman and CEO Rick Wagoner said last month that GM would have to make adjustments, particularly in metal stamping factories.

Further cuts could shore up GM's share price, which lost nearly half its value this week, plunging to the lowest level in 59 years. The shares fell 31 percent to $4.76 Thursday and dropped to $4 in the first minutes of trading Friday, the lowest level since Nov. 16, 1949, according to the Center for Research in Security Prices at the University of Chicago. They rebounded to end six straight losing sessions and close at $4.89, up 13 cents, or 2.7 percent.

Industry analysts say closing factories or cutting shifts will help GM reduce costs and preserve cash at a critical time with the company losing billions and burning up cash at an alarming rate.

GM had $21 billion in cash and $5 billion available through credit lines at the end of June for total liquidity of $26 billion but has been burning up cash at a pace of more than $1 billion a month.

The company announced a plan in July that calls for cutting $10 billion in costs and raising another $5 billion through asset sales and borrowing through 2009.

Mark Warnsman, an auto analyst with Calyon Securities, said further production cuts are consistent with what GM and other automakers have been doing all year _ cutting factory capacity to match lower sales.

"I think it's a positive sign that GM is biting the bullet," he said. "For GM going forward, they're going to have to use everything available to them."

So far this year, GM's U.S. sales have sank with the overall market. Through September, GM sold 18 percent fewer vehicles than it did in the same period last year. U.S. auto sales overall are down 13 percent through September, and J.D. Power and Associates on Thursday reduced its projections to 13.6 million this year and 13.2 million in 2009, down from 16.1 million units in 2007.

Rumors and fear of cuts have been circulating through GM factories for months, especially those that make parts for trucks.

"Everybody's a little bit concerned, I'm sure they are," said Bob Allard, who helps to build four-speed automatic truck transmissions at GM's Willow Run facility, about 35 miles west of Detroit.

GM is relying more and more on six-speed transmissions to make its trucks more fuel-efficient, and industry analysts have said plants making four-speeds are vulnerable. Also vulnerable are those making large V-8 engines for trucks, as well as plants that stamp out truck parts.

GM has been shifting its truck-heavy lineup to satisfy a market leaning toward smaller, more fuel-efficient vehicles. The company has increased production of small and midsize cars, plans to start building the new compact Chevrolet Cruze in 2010, and is building a new plant in Flint, Mich., to make four-cylinder engines for the Cruze and the Chevrolet Volt electric car.

Last month, Wagoner would not say if more factories will be closed or if GM would merely reduce shifts or assembly line speeds. But analysts and automakers have said it's not efficient to run factories on only one shift, which GM is doing in many locations.

Warnsman said he would not be surprised if there are further plant closures. Continued...