Gen. Paul F. Gorman, the Army's top officer in Central America and an architect of U.S. policy there, will retire in a few months, a Pentagon spokesman said yesterday.

Gorman's departure, rumored for several months, will remove one of the most forceful advocates of an increased U.S. military presence in Honduras and the region. Gorman, a smart and self-confident war hero who never spoke to reporters, is credited with devising the plan for lengthy U.S. military exercises in Honduras that has allowed the Army to maintain a permanent presence there without formally establishing new bases.

The Pentagon confirmed yesterday that another of those exercises, Big Pine 3, will take place in "early spring," involving several thousand U.S. troops and lasting about two months. Currently between 1,300 and 1,500 U.S. troops are in Honduras, Lt. Col. Richard Lake, a Pentagon spokesman, said, although no exercises are now taking place.

Michael I. Burch, assistant secretary of defense for public affairs, also confirmed that the aircraft carrier USS Nimitz is steaming toward the Caribbean, but declined to give details. Other officials confirmed that the Nimitz and battleship Iowa both will spend time off Central America with their battle groups during the next few weeks, the first "presence" missions by the U.S. fleet in that sensitive area since last summer.

"I would not characterize the mission as a show of flag," Burch said. "We're operating practically in our own home waters and off our own coasts."

Sources said that Gorman is likely to be succeeded by Lt. Gen. John R. Galvin, 55, commander of VII Corps in Europe. Galvin, an infantry officer and -- like Gorman -- a West Point graduate, commanded the 24th Infantry Division at Fort Stewart, Georgia, before getting his third star and moving to Europe in the summer of 1983.

Burch said that Gorman, 57, decided to retire now, after 35 years in the Army, despite entreaties to stay from President Reagan, Defense Secretary Caspar W. Weinberger and Gen. John W. Vessey Jr., chairman of the Joint Chiefs of Staff. Burch was not asked about rumors that some State Department officials were eager for the general to resign, but he appeared to be trying to dispel them.

"All feel -- and I'm speaking for both the State Department and Defense here as well as everyone in the administration -- that he has done what the commander-in-chief asked him to do, and has done it extremely well," Burch said. "The secretary of defense feels that his retirement is a great loss to the nation, but the general simply could not be persuaded to stay on."

Other officials said there was some "grumbling" in the State Department because of Gorman's active diplomacy. Some felt that Gorman, occasionally referred to resentfully as the "viceroy" or "proconsul," sometimes undercut ambassadors with his general-to-general encounters in Guatemala, Honduras and elsewhere.

But those officials said there was no pressure from Secretary of State George P. Shultz or other top officials for Gorman to resign.

Gorman assumed control of the Southern Command in Panama in May 1983 and immediately began increasing the influence of the command, once a sleepy backwater dedicated primarily to defense of the Panama Canal. Gorman won his fourth star at the same time, a sign of the administration's desire to upgrade what had been a three-star command.

Gorman's familiarity with the workings of the Reagan administration -- he was assistant to the chairman of the Joint Chiefs from 1981 to 1983 -- and his earlier service in the CIA made him a formidable bureaucratic player in Central American policy, officials said.

Burch said he believes that Gorman plans to take up farming.