Retired Navy Vice Adm. William V. O'Regan, 77, who commanded a World War II wolfpack of submarines in the Pacific known as the "Mickey Finns", died Friday at the Veterans Administration hospital in Palo Alto, Calif.

Adm. O'Regan took command of Submarine Division 42 in 1943.

By June, 1944, the Japanese were on the defensive, having lost the Battle of the Philippine Sea. It was decided that the then Capt. O'Regan in command of submarines Guardfish, Piranha, Thresher, and Apogon should pursue Japanese commercial shipping.

In an area known as "Convoy College" that extended across the East China Sea from Luzon Strait to Formosa and the coast of China, the Mickey Finns found good hunting. In a period of five days the submarines sank 41,000 tons of Japanese shipping.

The unit eventually accounted for 110,700 tons. The Mickey Finns sank 16 enemy ships and badly damaged three others.

For his leadership, Adm. O'Regan received the Navy Cross. "Skilled and agressive in combat, Capt. O'Regan successfully developed attacks through alert enemy escort ships and their severe counter-attacks," according to the Navy Cross citation.

The Mickey Finns received a Presidential Unit Citation for their work between June and August, 1944, in the waters between Japan and Formosa.

After the war Adm. O'Regan moved to Washington, and served here until 1947 when he left for tours of duty in the Middle East.

From 1950 to 1952 he worked here in the office of the chief of naval operations as an assistant director of the office for strategic plans.

In September, 1952, he was named commander of Cruiser Division No. 5. As a result of his command of these heavy cruisers off the North Korean coast he received the Gold Star to add to a Legion of Merit.

Adm. O'Regan returned to Washington in 1953 as assistant chief of naval operations for logisticars, where he served until 1957. He retired in 1958.

He was a native of New York and graduated from the U.S. Naval Academy in Annapolis in 1923.

While at the academy he was known as a mathematics whiz and was three-time president of his class.

He was captain of the boxing team his senior year, and once, while serving aboard ship beat Jack Sharkey in a Navy match.

After graduating from the academy he served aboard the battleship Wyoming and taught mathematics at the academy. At the outbreak of World War II he was commander of submarine repair unit No. 1 in New London, Conn.

After retiring from the Navy, Adm. O'Regan earned a master's degree in mathematics at Stanford and then taught high school in California until 1972.

He is survived by two sons, William V. Jr., of Bowie, and Joseph E., of Sunnyside, Calif., five grandchildren and one great-grandchild.