Morton E. Yohalem, 74, a Washington lawyer since 1954 who specialized in the practice of securities law, died Wednesday at George Washington University Hospital after a heart attack.

Mr. Yohalem came to Washington in 1924 serving as chief counsel and then director of the public utilities division of the Securities and Exchange Commission.

He became special deputy to the administrator of the Reconstruction Finance Corporation in 1952, and was put in charge of formulating a plan for the withdrawal of the government from the field of synthetic rubber production.

The plan he helped develop provided for turning over of government owned synthetic rubber facilities, which were started during World War II, to private industry. "Fortune" magazine described the plan as "masterful" in a 1953 piece.

Mr. Yohalem joined the New York law firm of Marshall, Bratter, Greene, Allison and Tucker in 1954 as a resident partner. He remained active in the firm in Washington until the time of his death.

Mr. Yohalem was a native of New York City and was a graduate of Cornell University and New York University's law school. He worked as a lawyer for the trustee-in-bankruptcy of the International Match Corporation before joining the New York office in the SEC in 1938.

He is survived by his wife of 53 years, Florence, of the home in Washington; two sons, Joel, of Bethesda, and Harry, of Washington, and three grandchildren.