Clarence A. Arata, 73, a retired executive vice president of the Greater Washington Board of Trade and a former executive director of the Washington Convention and Visitors Association, died of cancer April 1 at Sibley Memorial Hospital. He lived in Arnold, Md.

As an executive in the important tourism and convention industries, Mr. Arata was known as a staunch supporter of Metro, the new Convention Center and other projects designed to revitalize the downtown neighborhoods.

The center, he said when he retired from the Board of Trade in 1977, would "increase the city's posture as a convention city." He noted that such gatherings here already have made Washington "one of the major tourist attractions and one of the most important cities in the world."

He was named executive vice president of the Greater Washington Board of Trade in 1971. He was executive director of the Washington Convention and Visitors Association from 1946 until 1971.

Mr. Arata previously had served as assistant manager of the Washington Convention and Visitors Association and as executive secretary of the Board of Trade.

He was past president of the National Association of Travel Organizations and the International Association of Convention Bureaus. He was a member of the American Chamber of Commerce Executives, the American Society of Association Executives and the Washington Trade Association Executives. He was a Mason and a member of the Almas Temple of the Shrine.

Mr. Arata was a native of Cincinnati, and a graduate of the University of Cincinnati law school. He moved to Washington in 1937. He served with the Navy during World War II.

His marriage to Gretchen Arata ended in divorce.

Survivors include his wife, Lois, of Arnold; two sons by his first marriage, Jim E., of Bethesda, and Thomas W., of Potomac, and four grandchildren.