Leucadia National, a New York insurance firm,...

Leucadia National, a New York insurance firm, disclosed that it had acquired a 5.3% stake in GATX Corp. and is considering seeking control of the Chicago-based rail-car leasing and shipping firm . . . United Airlines denied a charge by Continental Airlines that United had sought to harm Continental by not including Continental’s new winter fares in its Apollo computer reservation system . . . Shareholders of Garden Grove-based Swedlow Inc. have approved an agreement and merger plan under which PPG Industries will acquire Swedlow for $32.60 a share.