Federal personnel director Constance Horner said she failed to remember key details about the firing of her predecessor and refused at a congressional hearing yesterday to discuss White House pressure to oust Loretta Cornelius because such action would "breach the president's absolute right to terminate employes."

Cornelius was fired Feb. 5 under pressure from conservatives who blamed her for the downfall of Donald Devine, former director of the Office of Personnel Management.

"Mrs. Horner has learned the lesson that if you tell the truth to Congress you get in trouble," said Rep. Barney Frank (D-Mass.), chairman of the employment subcommittee of the Government Operations Committee. "Her memory is distressingly convenient."

"Mrs. Horner didn't carry it off too well . . . . By not being specific she hurt herself," said Rep. Howard C. Nielson (R-Utah), ranking Republican on the subcommittee. "Executive privilege is used all the time. I don't like it myself. Let's get the sequence. Let's find out if anyone was harassed."

Cornelius testified last summer that Devine asked her to lie about knowing that he had delegated power to run OPM to himself while he was awaiting reconfirmation. Devine, a favorite of conservatives, withdrew his nomination a short time later. After that, Cornelius testified, she was harassed by anonymous allegations that she used her staff for personal work and her car for personal business.

Horner tried to force Cornelius to resign by threatening to send an inspector general's report about the allegations to the Justice Department and release it to The Washington Times, Cornelius testified. Horner said yesterday that she was required to release the report because of a Freedom of Information Act request from the newspaper and denied trying to blackmail Cornelius to quit.

Cornelius said she has reimbursed the government for $29 she spent in improper travel and that the other allegations were unfounded.

William Hunt, former associate OPM director of administration, testified that he was fired because he had "said more than was necessary" to back up Cornelius' testimony at Devine's reconfirmation hearing. A political appointee, Hunt said he had received honors, awards, cash and promotions every year at OPM until he was called into Horner's office Oct. 21 and told to look for a new job.

Hunt testified that Horner told him, " 'Let me call presidential personnel,' then paused "and said it was not a good idea, the White House was not pleased, that I had said much more than was needed about Devine and 'they didn't think you were a good presidential appointee.' "

"I don't remember that," Horner testified. "It sounds imprudent, and I usually am not." Asked about her memory, Horner said, "People who are worried take notes. I did my duty and forgot about it."

Horner said she fired Hunt because she was not satisfied with his work. "I gave him several months to find another job."

"This is something that is not legislatively reviewable by the Congress," Justice Department spokesman Terry Eastland said. "We advised Horner to say the Congress has no authority to inquire into the removal of an executive branch official who was appointed by the president.