Philip P. Marenberg, 71, a former government official who engaged in the private practice of law in Washington for about 30 years before retiring in mid-1970s, died Wednesday at George Washington University Hospital after a heart attack. He was a resident of Washington.

He specializes in representing civil service employes in personnel matters before federal administrative and law courts.

Mr. Marenberg had served on the National Committee on Civil Service of the National Association of Internal Revenue Employees (NAIRE). He was a member of the D.C. Bar Association, and from 1956 to 1957 chaired its Committee on Civil Service.

He was the author of the 1958 book, "Legal Aspects of Employee Disciplinary Actions," and the coauthor of "Your Federal Civil Service," published in 1940.

Mr. Marenberg was a native of New York City and a 1930 graduate of New York University. He came to Washington later that year and worked for the government while attending Georgetown University's law school, from which he graduated in 1935.

After spending 12 years with the old Civil Service Commission, he joined the War Manpower Commission in 1942. Two years later, he went on active duty with the Army and worked with the Manhattan District, the code designation for the development of the atomic bomb, and Army's Bacteriological Warfare Center. He spent a year as a civilian with the old War Department before entering private practice in 1947.

Mr. Marenberg's wife, Sadie, died in 1956. His survivors include a son, Paul D., of Washington; a daughter, Ruth B. Moe of Reston and Copehagen, and three grandchildren.