MICHIGAN GENERAL <MGL> TO SELL KRESTMARK UNIT Michigan General Corp said it agreed to sell substantially all of the assets and certain liabilities of its Krestmark subsidiaries to LCB Holdings Inc for 6.5 mln dlrs cash. Sale of Texas-based Krestmark, a maker of doors, door frames and other products, will allow Michigan General to concentrate on retailing through its Diamond Lumber and Savannah Wholesale units. Proceeds of the sale will be used to reduce debt. The deal is subject to execution of a definitive agreement. Krestmark had revenues of about 40 mln dlrs and operating losses of three mln dlrs in 1986, the company said. It has been accounted for as a discontinued operation since last September. Dallas-based LCB is a privately-held maker of structural steel joists and rack and storage handling systems. Michigan General also said its Diamond Lumber homebuilding products retail unit closed nine unprofitable stores in the first quarter and reduced its headquarters staff by 10 pct. The nine closed stores, which had pretax operating losses of 1.7 mln dlrs in 1986, are being sold to provide cash for operations. About 4.5 mln dlrs of inventory from the stores is being transferred to other locations, the company said.