Lawrence M. Lenkin, an executive of the Lenkin Construction, Development and Business Management Companies in charge of apartment management in the District of Columbia, died suddenly Saturday morning following a heart attack. He was 47.

Mr. Lenkin was a native of the District and long prominent in real estate development and management. A graduate of Roosevelt High School. Class of 1948, he enlisted in the Navy and upon discharge attended the University of Maryland.

Following his schooling, Mr. Lenkin joined the family construction firm founded by his late father, Harry Lenkin. The family enterprises have long been major developers of Washington real estate, including downtown office buildings.

Active in charitable affairs, Mr. Lenkin was a member of the board of directors of the Kaufmann Camp for Children and a member of the advisory board of the Kennedy Bank and Trust Company of Bethesda. He also was a member of Adas Israel and B'nai Israel Congregations and the Woodmont County Club.

Mr. Lenkin is survived by his wife, Andrea, of the family home in Bethesda; two sons, Michael and John; a daughter, Hope; a sister, Natalie Clayman of Bethesda; and a brother, Melvin, also of Bethesda.

The family suggest that expressions of sympathy be in the form of contributions to the American Heart Fund or other charities.