Clive Newton Thompson Jr., 55, a government representative with the Phillipsburg division of Bell & Howell Inc. and a volunteer coach of athletics for youngsters, died Wednesday at Arlington Hospital following a heart attack.

Mr. Thompson was born in Wasnington and graduated from McKinley Technical High School here. He was a lieutenant j.g. in the Navy during World War II and then attended the University of North Carolina at Chapel Hill.

Following his graduation in 1948, he worked for the Underwood Corp. and for Elliott Business Machines. He joined Bell & Howell about 1969. He worked for that firm's Baumfolder division before transferring to the Phillipsburg division.

He had been an athlete in high school and kept up his interest in sports in later life. He lived in McLean and was a coach with the McLean Little League and the Babe Ruth League and with Boys Club teams. A golfer, he was a member of the Washington Golf and Country Club for 25 years.

Survivors include his wife, Amelia B., of McLean; four daughters, Joyce T. Murphy of Sterling, Va., Carol T. Roberts of Alta Loma, Calif., Kristi L., of Arlington, and Jennifer L., of New York City; three sons, Clive N. III, of Ambler, Pa., and Brian J. and James D., both of McLean; a sister, Mary E. Wilbanks of Riverdale, and three grandchildren.

The family suggests that expressions of sympathy be in the form of contributions to a youth athletic program of one's choice.