Dr. Murdock Head, who was convicted last week of particpating in a criminal conspiracy, has stepped aside temporarily as executive director of the Airlie Foundation, and relinquished his day-to-day duties as a department chairman at George Washington University.

Head, 55, had directed the Airlie Fondation, a conference center and retreat based near Warrenton, Va., since it was started in 1960. He has been replaced as executive director by Frank Kavanaugh, formerly an associate Airlie director. The change was effective Monday.

Kavanaugh said in a telephone interview that Head's decision to step aside would allow the former Airlie chief to devote time to appealing his conviction by a federal jury and would also remove a possible obstacle to future financial aid to Airlie from government and private organizations.

Head has also temporarily relinquished his day-to-day duties as chairman of the George Washington University department of medical and public affairs, according to Airlie and university officials.

A university spokeswoman said that the department's vice chairman, Elgberry Waters Jr., will serve as acting chairman until Head has appealed his conviction. Head, however, will retain the title of department chairman and professor, the spokeswoman said.

Head was convicted last week by a U.S. District Court jury in Alexandria of a single conspiracy count. He is scheduled to be sentenced next Wednesday by Judge Oren R. Lewis.

The charge on which Head was convicted alleged that he had conspired to give bribes to two members of Congress and to violate tax laws. The Washington Post has reported, however, that the federal jury did not believe Head was guilty of scheming to bribe the two congressmen -- Rep. Daniel J. Flood (D-Pa.) and former Rep. Otto E. Passman (D-La.).

Instead, the Post reported, the jurors interpreted the conspiracy count more narrowly. The jury concluded, according to The Post's account, that Head was guilty of conspiring to commit tax infractions, including arranging an improper $11,000 loan to a now-retired Internal Revenue Service agent.

The Airlie Foundation and organizations linked with it have previously received more than $15 million in federal funds, mainly from the Agency for International DEVELOPMENT (AID and the Department of Health, Education and Welfare. The federal contracts and grants have centered on educational projects, including numerous motion pictures.

It was unclear yesterday whether Head's conviction would jeopardize Airlie's financial prospects. An AID source said that Head's conviction would not prevent future AID contracts with Airlie and its allied organizations, provided that Head were not directly involved in a proposed project. HEW general counsel Richard I. Beattie said it was not immediately clear whether Head's conviction would have any effect on further HEW financing of Airlie projects.

Kavanaugh, nevertheless, expressed concern that Head's conviction may make federal officials reluctant to sign contracts or grants with Airlie and its affiliated organizations. "I think, in practice, they find it hard to put their pen to the [contract or grant] paper," Kavanaugh said.