GAF sought to topple Carbide’s takeover defense.

GAF Corp. filed suit in U.S. District Court in New York, charging that Union Carbide and its directors had illegally failed to treat all shareholders equally. GAF’s suit alleged that Carbide’s two-tiered defense was intended to entrench current management, frustrate GAF’s bid and confuse shareholders. The suit also seeks to overturn 5-month-old conditions of Carbide’s employee pension fund that would prevent an unfriendly buyer from using $500 million in surplus funds to help finance a takeover. GAF is attempting a $4.3-billion takeover of Carbide.