Defense Secretary Caspar W. Weinberger has decided to refuse to allow reporters to accompany him on his five-day trip to the Persian Gulf this month, according to Defense Department officials.

One official said Weinberger is barring news media representatives from traveling on his airplane because "he wants to make it a low-key visit."

The trip, which is to include visits to Saudi Arabia, Bahrain and at least one ship in the gulf, is expected to attract wide media coverage in the region, however. Department officials said Weinberger tentatively plans to meet with reporters there during the trip.

The Pentagon has not officially acknowledged the trip, which sources said is to begin Sept. 23.

Navy Secretary James H. Webb Jr., currently visiting the gulf, also denied reporters' requests to accompany him on the trip.

Pentagon officials said some of the nations to be visited by Weinberger are sensitive about media coverage, a factor that Weinberger likely considered.

The United States has been involved in delicate diplomatic negotiations with several gulf nations, including Saudi Arabia, over basing rights and other military agreements.

In another incident related to U.S. gulf operations, the Conquest, a mine sweeper en route to the region, smashed into the side of its tow ship yesterday in the Pacific Ocean west of Hawaii, causing a disabling 15-foot gash in the hull, according to Pentagon officials.

The Conquest was one of three mine sweepers being towed to the gulf by the tank landing ship Barbour County to assist in Navy mine-hunting operations. Three more mine sweepers are being towed there from the Atlantic coast.

Pentagon officials said the tow ship will continue the journey with the remaining two mine sweepers, while the Conquest and its crew returns to Pearl Harbor for repairs. No injuries were reported, officials said.

The incident occurred while the Conquest's crew was attempting an "emergency break-away" as the wooden-hulled ship drifted too close to the Barbour County during refueling, a Navy official said. The crew could not divert the mine sweeper in time to avoid the crash, officials said.

The mine sweepers' engines are operated to speed the trip while being towed, officials said.