Martin M. Tank, 63, a tired foreign service officer who served with Agency for International Development missions in Africa and the Far East, died Monday at his home in Washington. He had a heart ailment.

Mr. Tank was deputy director of the foreign aid mission to Libya from 1958 to 1960, then came to Washington where he was director AID's military assistance division for the next three years.

He went to Bangkok, Thailand, in 1964 as deputy director of the operations mission there. From 1968 to 1970, he was program officer and economist with the AID mission in Saigon.

After returning to Washington in 1970, he was an economic plans officer. From 1973 until retiring two years later, he was policy chief of the planning and review division in the State Department's office of International Organization Affairs.

For the last five years he had been an economic consultant on developing nations to the State Department.

Mr. Tank was born in Winnipeg, Canada, to American parents. He was reared in Milwaukee, and earned both bachelor's and master's degrees at the University of Wisconsin. He also attended the National War College.

After serving with the Army in World War II, he was an economist with military government in Berlin. He worked for the Marshall Plan and NATO in Paris from 1949 to 1955. He was an economic counsellor at the U.S. Embassy in London before going to Libya.

Survivors include his wife, Marelyn, a daughter, Holly, and a son, Jeffry, all of Washington.

The family suggests that expressions of sympathy be in the form of contributions to the National Cathedral Building Fund.