Arthur Greenbaum, a leading real estate attorney who helped expand Greenbaum, Rowe, Smith & Davis from a family-run enterprise into a full-service business firm, died Tuesday at age 91.

Greenbaum became a key player in the state's real estate industry through the representation of major homebuilders such as Hovnanian Enterprises and Union Valley Corp. after joining the family firm in 1950. He built a reputation as an authority in real estate law, and had several cases before the state Supreme Court, including New Jersey State Bar Association v. New Jersey Association of Realtor Boards, the landmark 1983 ruling giving buyers and sellers of residential real estate a three-day attorney-review period before their transaction becomes final.

While establishing his own career, Greenbaum also joined with his brother, Robert, and their father, William, to build the firm's prominence as a real estate powerhouse. Greenbaum and his brother were the impetus behind the firm's relocation in the late 1960s from Newark, where their father established his law practice in 1914, to its current home in Woodbridge, in the central part of the state, because “that's where a lot of development was going on,” said Mark Sobel, the firm's co-managing partner.