On the eve of trial, a Manhattan judge has thrown out most of a lawsuit filed against Winston & Strawn by a onetime rainmaking partner who claimed the firm sharply reduced his pay in violation of a special compensation agreement.

Anthony F. LoFrisco, a partner in the New York office of Chicago-based Winston & Strawn, had long been one of the highest-paid lawyers at the firm, owing to a 1994 agreement that tied his compensation to work the firm performed for the General Electric Co.