Lear Siegler reported that it sold all...

Lear Siegler reported that it sold all of its holdings in Lone Star Industries, consisting of 1.208 million shares of common stock with a current market value of $30.7 million, to an unidentified party . . . The Justice Department has approved the merger of Muse Air with Southwest Airlines, saying that, without the deal, Muse may not be able to meet next month’s financial obligations . . . Tiger International reported that it had consummated its previously announced settlement of its $148-million obligation to North American Car . . . Prime Computer announced that it has filed suit in U.S. District Court in Denver against Tristan Dynamics of Parker, Colo., for alleged copyright infringement and misappropriation of trade secrets . . . Hospital Corp. of America and Healthgroup International reported a definitive agreement for HCA to acquire Healthgroup . . . ASK Computer Systems said it has learned that complaints have been filed against it alleging securities law violations in connection with its February, 1985, public offering . . . The American Iron and Steel Institute said steel production rose 1.9% to 1.8 million tons in the week ended May 18.