Philip M. Ritz, 65, a retired Commerce Department economist and a former economic consultant, died of cancer Saturday at Shady Grove Adventist Hospital in Rockville. He lived in Potomac.

Mr. Ritz also was a specialist in statistics and the co-author of "Problems in a Price Control: Stabilization Subsides."

He moved to this area in 1940 to work for the Civil Service Commission and was an associate economist with the old Office of Price Administration during World War II.

Mr. Ritz then worked for the old Bureau of the Budget and was a senior economist for the Bureau of Labor Statistics. From 1953 until 1973, when he joined the Commerce Department, he was a consultant for the Conference of Economic Progress and the National Planning Association.

He was chief of the Division of Inter-Industry Economics for the Commerce Department's Bureau of Economic Alalysis until his retirement two months ago for reasons of health.

Mr. Ritz was born in Hibbing, Minn., and graduated from Milwaukee State Teachers College. He earned a master's degree from the University of Wisconsin and worked on a doctorate in economics at American University.

He was an organizer and former president of an early interracial cooperative in Washington in the 1940s and was a member of the board of the Greenbelt Consumer Cooperative and the Northwood Housing Co-op.

Mr. Ritz was a charter member of the Lakewood Country Club in Rockville and had won a golf tournament there in August.

Survivors include his wife, Bernice E., and a son, Michael, both of Potomac; a daughter, Beverly Ritz-Pell of Santa Monica, Calif., and a brother, Erwin, of San Francisco.

The family suggests that expressions of sympathy be in the form of contributions to the Vincent Lombardi Cancer Research Center at Georgetown University Hospital.