ComPhibPac, also seen as COMPHIBPAC, was the official U.S. Navy abbreviation for "Commander, Amphibious Forces, Pacific Fleet."
Amphibious forces under the command of ComPhibPac are known as PhibPac or PHIBPAC. One of PhibPac's subordinate commands during World War II was Transports, Amphibious Force, Pacific Fleet, or TransPhibPac. The commander of TransPhibPac was known as ComTransPhibPac.
PhibPac was amalgamated into the new command Commander, Naval Surface Forces Pacific, probably in the mid 1970s.
References
This article incorporates text from the public domain Dictionary of American Naval Fighting Ships.