Labor Secretary Raymond J. Donovan, calling jawboning an "insult" to the free-enterprise system, said yesterday his agency should stay out of collective-bargaining talks, including those negotiations that involve federal employees.

"We would like to facilitate these things, to keep the lines of communication open," Donovan told reporters at a luncheon interview. But he said he's against "interjecting ourselves" into contract negotiations or "jawboning" labor leaders in an attempt to win peaceful, less costly settlements.

Federal intervention in contract talks "doesn't serve the collective-bargaining system well," said Donovan. He added that he thinks "management and labor really believe they have much more in common" on contracts matters than is publicly known or acknowledged.

The labor secretary's comments came as representatives of the United Mine Workers of America and the Bituminous Coal Operators Association were working against a 12:01 a.m. deadline today in an effort to produce an new three-year contract covering the eastern and midwestern soft-coal industry.

Donovan said his department had been monitoring those talks, as well as negotiations between the 17,000-member Professional Air Traffic Controllers Organization and the Federal Aviation Administration, whose three-year agreement expired Sunday.

Upcoming talks involving the American Postal Workers and other unions representing 600,000 postal employees -- the largest number of people involved in contract talks this year -- "probably will be difficult" because of proposed cutbacks in federal postal subsidies and other problems that will be brought to the bargaining table, Donovan said.

On other issues in his wide-ranging interview, the secretary said:

He would urge Japanese automakers to use "voluntary restraint" in exporting cars to the United States.

He "would be disappointed" if labor organizations, among them the AFL-CIO, succeed in their attempts to discredit President Reagan's "economic recovery" program, which Donovan believes in necessary to spur economic growth and to create more jobs.

He has moved "slowly but diliberately" to fill his major department posts, and the task should be completed within several weeks, or sooner.

One of his primary objectives is to better control spending at the Employment and Training Administration, the Labor Department's largest agency, which Donovan also said "needs strong management."