Chrysler might be considering closing the Kenosha engine plant sooner than planned, a local union official said on Friday.

Glenn Stark, UAW Local 72 president, said the company wanted to add up to 82 temporary employees here after Jan. 1 to boost production by 30 percent. That could lead to the Kenosha plant closing earlier in the fourth quarter 2010 than the original December 2010 date, he said.

In other Chrysler news, company officials reportedly want the Sterling Heights, Mich., plant to remain open past its original closing date, also December of next year. That plant produces Chrysler Sebring and Dodge Avenger autos, which use Kenosha-produced V6 engines.

That might suggest the Kenosha plant could stay open longer. However, Stark said those vehicles eventually will use the new Phoenix engine, built elsewhere. He said he hasn’t been told the Kenosha plant closing date would be altered.

A Chrysler representative said the company has not announced any changes to the original plans for closing. The original date came out of papers filed when the company was in bankruptcy earlier this year.

Stark added that anything could happen between now and the Kenosha factory’s closing date. He referred to the possible closing date as being nine months away. That would place the closing in the early fourth quarter of 2010. He said he believed the date would be earlier than next December because of the 30 percent increase in production.

“That tells me they’re trying to trim off a month or two,” he said.

The company said it had no comment on the Sterling Heights situation.

Published reports said the Michigan assembly plant would continue to operate into 2011, based on comments from United Auto Workers Vice President General Holiefield.

The union official on Thursday said there was an extension arranged beyond the closing date of the facility. Chrysler CEO Sergio Marchionne said that discussing an extension would be premature but there was a “potential” for a change in plans.

Chrysler came out of bankruptcy under control of the Italian company Fiat.