N. Eugene Otto, 61 an official of the Potomac-Electric Power Company who was active in civic organizations, died Monday at the Washington Hospital Center after a heart attack.

Mr. Otto had been the public relations manager in charge of special projects, including tours, budget work, and corporate contributions, since 1971.

He had joined Pepco in 1935 as an accounting clerk and transferred to the public relations department in 1953.

He had been president of the Bethesda-Chevy Chase Chamber of Commerce and the Bethesda Civitan Club. He had served as chairman of the Washington Board of Trade's Welfare Committee, on the board of the Montgomery County Health and Welfare Council, and as a delegate to the Montgomery County Civic Federation.

Mr. Otto was named the "Outstanding Man of the Year" by the Washington Junior Chamber of Commerce in 1954.

At the time of his death, he was a member of the board of trustees of Suburban Hospital and secretary of the Maryland-District of Columbia Utilities Association.

During World War II, Mr. Otto served as an infantry officer with the 79th Infantry division in Europe. He was awarded the Bronze Star Medal with two oak leaf clusters.

He was recalled to active duty during the Korean conflict. He was awarded the Air Medal with two oak leaf clusters while serving as an intelligence officer in Korea.

A native of Union Bridge, Md., Mr. Otto came to Washington at an early age. He attended George Washington University and was a graduate of Benjamin Franklin University.

Mr. Otto was a member of the Chevy Chase United Methodist Church and had served as a trustee of the Asbury Home and of the Methodist Union of Greater Washington.

He is survived by his wife, Vivian, of the home in Sumner; two daughters, Barbara Wege, of Silver Spring, and Ruth Ann Otto, of Miami, Fla., and one grandchild.

The family suggests that expressions of sympathy be in the form of contributions to Suburban Hospital or to the Methodist Board of Child Care, of the Chevy Chase United Methodist Church. CAPTION: Picture, N. EUGENE OTTO