Chrysler Corp. said yesterday it will close its Lynch Road assembly plant in Detroit this fall, idling another 2,280 workers.

It will be the seventh plant that the struggling No. 3 automaker has closed in its desperate attempt to cut internal costs and trim losses.

Unlike the previous closings, Chrysler said the Lynch Road shutdown may not be permanent. The action was blamed on a result of "a continuing decline in the North American market for full-sized passenger cars. In the event of a reasonably stable market, the Lynch Road facility could be reopened in future model years," Chrysler said.

The action also marks the likely withdrawal of Chrysler from the full-sized car market as it has been traditionally recognized.

The Lynch Road plant builds the full-sized Chrysler New Yorker and Newport, Dodge St. Regis and Plymouth Gran Fury. Sales of those models have slowed dramatically during the auto industry's year-long slump.

In other layoff announcements:

Two major steel producers reported more cutbacks. Jones & Laughlin Steel Corp. said it was making reductions at its Pittsburgh Works and at the nearby Aliquippa works. And Republic Steel Corp. said it has 2,900 employes "on layoff status," but declined to elaborate.

J&L didn't reveal the number of employes affected.

The cuts by J&L and Republic's report off layoffs followed reductions by other companies this year, which have put at least 16,000 steelworkers out of work.

Ford Motor Co.'s light truck assembly plant in St. Paul will be shut down for three weeks beginning Monday, and 420 employes will be laid off indefinitely when production is resumed.

Cummins Engine Co., the world's largest maker of diesel engines, said up to 1,500 more workers would be laid off May 30 at plants in Columbus and Seymour, Ind.

The company blamed a decline in orders for engines and parts.

Cummins already has 500 workers furloughed indefinitely. The engine firm normally employs 12,000 workers in the two cities.

Cummins also said there would be corresponding production cutbacks in plants in Charleston, S.C., Jamestown, N.Y., Fostoria, Ohio, and Cookville, Tenn. However, Cummins said it hasn't determined how many workers would be laid off in those plants.

Cessna Aircraft Co., said it was laying off 800 workers yesterday at its single engine manufacutring plants in Witchita and at Strother Field near Winfield, Kan.

This will bring to at least 2,250 the number laid off at Cessna's single-engine plants. Another 1,000 workers have been laid off at the company's Wallace Division to adjust inventories at that multiengine plant.

Layoffs and attrition have trimmed Cessna's work force, once the largest in Wichita, from a peak of about 20,000 in January to about 14,000.

AMF Inc. has laid off 390 of its Iowa workers, a reduction twice as large as it usually makes because of seasonal fluctuations in production.