One of President Clinton's first key acts as commander in chief, according to Rep. Barney Frank (D-Mass.), will be to issue an order today ending what Frank called harassment of homosexuals in the military.

Frank said last night the order would cause the military to halt efforts to require members of the armed forces to reveal their sexual orientation and force them out if they say they are homosexual or lesbian. The order also would require that the Pentagon stop asking sexual-orientation questions of new applicants for the services, Frank said.

Frank said the interim order is part of a two-step process that he predicted would please the gay community, which has long sought to be treated without discrimination.

A senior Defense Department official expanded on Frank's remarks last night, saying that Clinton would soon order preparation of an executive order permanently halting discrimination against military personnel "on the basis of sexual orientation."

The official said Clinton and his advisers have agreed the order would be prepared by Defense Secretary Les Aspin after consultations with senior military officers. The official added that the consultations were meant only to determine the timing for implementing the order, and would not alter the outcome.

"The aim is not to see if it's feasible to do it, not whether we should do it, but when we should do it," the official said on condition he not be named. He added that "as a practical matter, in the meantime, we would expect that discrimination will halt."

The official said that the lapse of time between the immediate, iterim measure and the executive order should be "more than adequate" to allow for discussions with military leaders on the issue.

Military leaders have long been opposed to permitting homosexuals and lesbians to serve in the military, and the four services have discharged many service men and women who are homosexuals or lesbians.