Retired Navy Rear Adm. William Granat, 87, a highly decorated combat veteran of World War II, died Friday in a hospital in Meadowbrook, Pa., after a heart attack.

Adm. Granat, than a captain, was named commanding officer of the battleship Colorado in 1943. One of the Navy's old battlewagons, it provided fire support for amphibious operations from Tarawa and Kwajalein to Guam, Saipan and Tinian.

While operating the Colorado as a fire-support unit at Tinian in the Narianas Islands, Adm. Granat earned the Navy Cross.

The citation said Adm. Granat "skillfully controlled the terrific gunpower of his ship, assailing strong coastal defenses with a smashing bombardment while maintaining his covering position throughout the maneuver. An indomitable leader, his superb ship-handling and unrelenting aggressiveness contributed essentially to the conquest of the vital Japanese stronghold."

Adm. Granat also was awarded the Purple Heart for the action at Tinian.

In 1944, he was ordered to the office of the secretary of the Navy. A year later he became a division chief in the Bureau of Ordnance, where he earned the Legion of Merit. He retired from active duty in 1947.

He then spent three years in Chicago followed by 10 years in Washington as a consulting engineer. He retired a second time in 1960. He was active in the Georgetown Civic Association until moving to Philadelphia about a year ago.

Adm. Granat was a native of California and a 1915 graduate of the U.S. Navel Academy at Annapolis. He served in the Mexican campaign in 1916 and aboard a cruiser in the Atlantic during World War I.

He was a graduate of the Navy's post-graduate school at Annapolis and studied metallurgy at Lehigh University in the early 1920s.

In the mid-1920s he was stationed at the Navel Gun Factory in Washington, worked at the Bureau of Ordnance from 1935 to 1938, and was executive officer of the Naval Proving Ground at Dahlgren, Va., from 1940 to 1941.He was stationed at the Bureau of Ordnance during the early years of World War I.

Survivors include his wife, the former Helena Griffin of Philadephia; a son, William G., of Wayne, Pa., and two grandchildren.