DETROIT, JAN. 27 -- Chrysler Corp. said today it will close its aging Kenosha, Wis., assembly and stamping plants by Sept. 30, eliminating about 5,500 jobs, because it has more factory space than it needs.

Kenosha was one of four assembly plants Chrysler acquired when it bought American Motors Corp. for nearly $1 billion in August. The plant has been building cars since 1902.

"This has been a hard decision because Kenosha has an excellent work force and has been producing cars of superior quality for Chrysler," said Gerald Greenwald, chairman of Chrysler Motors, Chrysler's automotive arm.

"The closing of any large manufacturing facility is a traumatic experience for a community," Greenwald said, adding, "We had to close Kenosha to keep competitive in what has become a shrinking U.S. automotive market."

Owen Bieber, president of the United Auto Workers union, said the closing "shows yet again the depth of the crisis that unmanaged trade and the lack of a progressive industrial policy are inflicting on this country."

Richard Dauch, Chrysler's executive vice president for manufacturing, said last month that the choice of a plant to close had been narrowed to Kenosha and the LeBaron plant in St. Louis.

"This takes care of the capacity problems that {Chrysler Chairman Lee A.} Iacocca mentioned in October. We don't have any other plant closings anticipated at this time," Chrysler spokesman Steve Harris said.

Wisconsin Gov. Tommy G. Thompson said that he was outraged by the decision and that Chrysler officials were turning their backs on his state. "Lee Iacocca and Gerald Greenwald are not living up to their commitment to Wisconsin, and I am not going to take this lying down," Thompson said.

Chrysler will keep an engine plant in Kenosha, preserving about 1,000 jobs there, the company said. The stamping plant that is closing makes components and body parts for the Kenosha plant.

The No. 3 automaker previously announced it would close a stamping plant in Milwaukee on March 31.