The Reagan administration's plan to use Egypt for launching U.S. military forces if Persian Gulf oil is threatened has run into trouble in the House, Pentagon officials said yesterday.

The House Appropriations subcommittee on military construction, they said, opposed in recent closed hearings the administration's request for $100 million in supplemental fiscal 1982 funds to improve the austere Egyptian military base and port at Ras Banas on the Red Sea.

In the view of the Reagan and Carter administrations, Ras Banas is vital as a staging area for any U.S. forces sent to handle a Persian Gulf emergency 10,000 miles from the United States. Ras Banas, directly across the Red Sea from central Saudi Arabia, would put U.S. forces in reach of Iran. By contrast, the island of Diego Garcia, which has been turned into a storehouse for U.S. military equipment, is more than 2,000 miles from the Persian Gulf.

In requesting the more than $100 million in supplemental 1982 money, Pentagon officials are telling congressional committees that it is essential to start building skeletal housing for U.S. troops at Ras Banas, enlarging the airport to accommodate giant Air Force transports and improving the port so it can handle warships.

The Pentagon plans to spend $500 million over the next four years on Ras Banas..

Sources connected with the House subcommittee, chaired by Rep. Bo Ginn (D-Ga.), confirm a reluctance to agree to the requested $100 million but said no formal vote had been taken.

Subcommittee arguments against Ras Banas include the Pentagon's failure to submit details for upgrading the base and the lack of formal assurance that Egypt will allow its use by U.S. forces in an emergency.

One Pentagon executive who deals with Congress said resistance to Ras Banas appeared to be part of the larger trend in Congress to pull back from one-sided commitments to protect overseas interests.

The executive said the trend includes objections to Ras Banas and suggestions to withdraw U.S. troops from Europe if allies there do not carry more of the defense burden.

However, Pentagon officials predicted yesterday that they would be able to persuade Congress that Ras Banas is vital to U.S. interests in the Middle East and Southeast Asia and thus they would get most of the $100 million.

The Senate has been more supportive of Ras Banas, leading Pentagon officials to believe that money for the base will emerge from a compromise House-Senate military construction bill even if the House panel's opposition evolves into a formal vote against the $100 million.