WASHINGTON (AP) _ The Securities and Exchange Commission said Tuesday it would conduct an internal investigation in the wake of a federal judge's finding of sexual harassment at the agency's regional office here.

Chairman David Ruder ordered the agency to hire two outside counsel: one to investigate possible disciplinary action against SEC officials involved in the case and another to review the agency's equal employment procedures, said spokeswoman Mary McCue.

The agency, meanwhile, is trying to reach a settlement with staff attorney Catherine Broderick, who won favorable judgment last month from U.S. District Judge John H. Pratt on her sexual harassment suit.

Pratt found that Ms. Broderick was forced to work in a ''sexually hostile'' atmosphere where male supervisors had romantic relationships with seceretaries, who received promotions and bonuses.

The judge also ruled that Ms. Broderick was passed over for promotions and given a negative evaluation after she complained.

Emphasizing that the agency still has not decided whether to appeal Pratt's decision, Ms. McCue said SEC lawyers are negotiating with Ms. Broderick's attorneys over how to resolve the case.

Pratt ordered both sides to submit proposals for compensating Ms. Broderick, remedies which could promotions and back pay.

A hearing, which was scheduled for Wednesday, was postponed until June 16 to give both sides more time to discuss a way to resolve the case, Ms. McCue said.

Following the ruling, Ruder, who became chairman last year, said he was distressed by the judge's decision.

The events covered by the lawsuit occurred during the tenure of John S.R. Shad, Ruder's predecessor who is now U.S. ambassador to the Netherlands. Pratt found that Shad and the agency's executive director, George Kundahl, were aware of Ms. Broderick's allegations in early 1984.

A 1986 investigation by the SEC's equal employment opportunity office found ''no nexus between (Ms. Broderick's) complaint and the other activities that were going on in the office.''

Pratt concluded that two officials of the Washington regional office in Arlington, Va., made sexually suggestive remarks to Ms. Broderick.

He also concluded that the testimony of several officials was ''deserving little credence'' and in the case of one was was ''in material respects false and incredible.''