Henry J. Tasca, 66, a former U.S. ambassador to Morocco and to Greece, was killed Wednesday in an automobile accident near Lausanne, Switzerland.

News agencies quoted Swiss police as saying the accident occurred when the car Mr. Tasca was driving and another vehicle collided at an intersection. Mr. Tasca's son, John, and the driver of the other vehicle were injured and hospitalized in Lausanne, reports said.

A career diplomat, Mr. Tasca had wide experience in various economic and political assignments. He was the Treasury Department representative to the U.S. Embassy in Rome from 1945 to 1948, and then an adviser to Ambassador W. Averell Harriman when the latter was the U.S. special representative in Europe for Marshall Plan aid.

In 1953, Mr. Tasca was assigned to Korea. Later, as director of the U.S. Operations Mission to Italy, he was in charge of U.S. economic assistance to that country. From 1956 to 1960, he held a similar post in Bonn, Germany.

From 1960 to 1965, when he became ambassador to Morocco, Mr. Tasca was deputy assistant secretary of state for African affairs. He was ambassador to Greece from 1969 to 1974.

Mr. Tasca's service in Greece was marked by controversy. His confirmation by the Senate for that post was held up because of reluctance to send an envoy of ambassadorial rank to a country ruled by a military junta.

His service in Greece ended with his abrupt recall and resignation from the Foreign Service following disputes about the overthrow of Archbishop Makarios as president of Cyprus and by events in Greece. The overthrow of Makarios led to a Turkish invasion of Cyprus.

After leaving the State Department, Mr. Tasca lived in Rome and engaged in business.

He was born in Providence, R.I. A graduate of Temple University, he earned master's and doctoral degrees from the University of Pennsylvania. He also studied at the London School of Economics.

Mr. Tasca began his career at the State Department in 1937 as an economic analyst with the division of trade agreements. He later was assistant director of a trade regulation and commercial policy project at the Rockefeller Foundation. In 1940, he returned to the government as economic adviser to the National Defense Commission. He served in the Navy during World War II and was a lieutenant commander when he left the service.

Mr. Tasca was fluent in French, German and Italian. He published several books on international trade.

In addition to his son John, Mr. Tasca is survived by his wife, the former Natalina Federici, and three other children, Ann, Eileen and Elia.