NORMAL - Contract negotiations between Mitsubishi Motors North America and its auto workers ended Saturday evening without an agreement.

Bargaining members of the United Auto Workers Local 2488 unanimously rejected the company's latest offer made at 12:30 p.m. Saturday. But union officials are telling its 1,261 members to return to work anyway.

"Workers are to report to work as regularly scheduled," said a recorded message left for callers to the union hall in west Bloomington.

The original contract expired Aug. 28, but a subsequent extension was approved and expired at 11:59 p.m. Friday. The two sides have been in negotiations since July 14 but a marathon session started on Friday. That session ended at 3 a.m. Saturday and resumed again around noon, before the latest proposal was rejected.

The talks are reportedly centered on issues including wage and benefit cuts, and a two-tier wage system. A statement issued Saturday night by UAW officials in Detroit said the bargaining committee remains ready to continue talks.

"In 2006 UAW members made concessions worth millions of dollars to improve Mitsubishi's bottom line," UAW Vice President Jimmy Settles said in the statement. "So it's extremely disappointing that this latest proposal asks these loyal workers for the kind of drastic cuts that would have a devastating impact on their lives and on the communities in which they live."

MMNA spokesman Dan Irvin said no new negotiations have been scheduled, and had no idea when talks might resume. He declined comment on the UAW bargaining committee's rejection of the latest proposal.

"By definition we are still in negotiations and so I am not going to discuss it," Irvin said. He added that the company is expecting employees to report to work as usual Monday.

Attempts to reach Local 2488 President Ralph Timan were unsuccessful Saturday. UAW officials in Detroit also could not be reached for comment.

In August, 97 percent of union members voted to authorize a strike, according to its Web site. The vote is a procedural step during the negotiation period, but now permits them to walkout if negotiations fail to result in a new contract.

To date, the only strike in Mitsubishi's history was a one-day walkout in 2001.

The current impasse in negotiations comes in the midst of a challenging year for both the company and the automotive industry. MMNA's U.S. sales through August have dropped 22.4 percent, from 93,724 vehicles in 2007 to 72,727 in 2008.

As a result of the diminishing sales, 105 union workers left the plant last month as part of a voluntary separation package. They received a lump-sum payment of $85,000 and three months of medical benefits.

The plant now has 1,565 employees. An average production worker earns about $50,000 annually, while the average maintenance worker earns about $60,000.

Mitsubishi also has had other difficult times in recent years, most notably when it laid off 1,200 workers and eliminated its second shift in 2004.

Then, as part of the 2006 wage and benefit cut agreement, workers narrowly approved a temporary $4 per hour pay cut, in return for the company's promise not to close the plant or seek involuntary layoffs through the end of the current contract.

The company used the money saved on wages to help fund the redesign of the 2009 Galant, which hit the dealerships earlier this year.

The wage cut was then restored in April, but management initially asked the union to consider a lump-sum payment instead.