DETROIT — The ink barely dry on a new four-year labor contract, Chrysler LLC says it plans to cut up to 12,000 jobs and remove four models from its lineup. The move stunned workers and suggests the now-private Chrysler won't hesitate to cut production and jettison vehicles that aren't selling well.

Chrysler said yesterday it will cut 8,500 to 10,000 hourly jobs and 2,100 salaried jobs through 2008, or about 15 percent of its workforce. The cuts come on top of 13,000 Chrysler layoffs that were announced in February.

Chrysler also will eliminate shifts at five North American assembly plants and cut four models, including the slow-selling PT Cruiser convertible and Dodge Magnum wagon.

Chrysler officials said falling demand for vehicles in the U.S. market made the cuts necessary. Chrysler's sales fell 3 percent in the first nine months of this year, according to Autodata Corp., and the company said it expects sluggish sales in 2008.

"We have to move now to adjust the way our company looks and acts to reflect a smaller market," Chrysler Vice Chairman and President Tom LaSorda, who led the company through the recent contract talks, said in a statement. "That means a cost base that is right-sized and an appropriate level of plant utilization."

Most workers will be offered buyout or early retirement packages. The details of those packages weren't released yesterday. Workers also could be offered jobs at other plants. About 1,100 of the salaried workers affected are temporary workers, who don't get severance packages.

"Our union will make sure our members receive all of the benefits and protections to which they are entitled under the contract," UAW spokeswoman Christine Moroski said.

Industry analysts said the cuts were long overdue to avoid overproduction, which leads to high inventories, angry dealers and costly incentives to move cars off dealers' lots. Chrysler, which became a private company in August, is now better equipped to make those changes, since it doesn't report earnings and can afford to take a short-term hit paying for buyouts. The private equity firm Cerberus Capital Management became the majority owner of Chrysler after buying an 80.1 percent stake from Chrysler's former partner, German automaker Daimler AG.

"One of the things that private equity does is give them the discipline and the financial patience to be able to do things like this," said David Cole, chairman of the Center for Automotive Research in Ann Arbor.

"It's about time. We're starting to see the kind of discipline that will build these companies into a sustainably profitable future," Cole said.

Aaron Bragman, an industry analyst for the consulting firm Global Insight, said Chrysler can now make decisions in a matter of hours instead of slogging through months of trans-Atlantic debate. Bragman said Chrysler also knew it would have to wait until the contract was ratified to make cuts or else workers would have voted down the contract.