James Vincent Hayes, a trial lawyer specializing in antitrust matters and a past president of the New York

County Lawyers Association, died Saturday at his home on the Upper East Side of Manhattan after a long illness. He was 85 years old.

At the time of his death, Mr. Hayes was a senior partner in the law firm of Donovan Leisure Newton & Irvine, which he joined in 1943. In one of the firm’s notable antitrust trial cases, he defended Howard Hughes and the Hughes Tool Company in a suit brought by Trans World Airlines.

Mr. Hayes was a native of Manhattan. He graduated from Fordham Law School and went into practice in 1926. He was assistant United States attorney for the Southern District of New York before being appointed a special assistant to the United States Attorney General in 1938.

Mr. Hayes was an officer and then president of the New York County Lawyers Association in the late 1960’s.

He is survived by his wife, the former Agnes Clare Brine; a daughter, Mary Ann Mumma of Larchmont, N.Y.; two sons, James B., of Scarborough, N.Y., and John V., of Manhattan; and 10 grandchildren.