Former President Ford has accepted a position as distinguished fellow of the American Enterprise Institute, a conservative think tank whose prestige has risen slowly but steadily for two decades, it was announced yesterday.

It is not clear how much time Ford will spend at AEI, but he will be salaried and have a secretary and a large, blue-carpeted office on the seventh floor of 1150 17th St. NW, just a few blocks from the White House.

According to William J. Baroody, president of AEI, Ford "can make major contributions to the work of oru scholars in a consultative and advisory capacity" because of his 28 years of experience in government.

Baroody is the father of William J. Baroody Jr., who was assistant to President Ford for public liaison. Another son, Mike, has been an executive assistant to Ford's 1976 running mate, Sen. Bob Dole (R-Kan.).

Baroody was uncertain whether Ford would do any writing at AEI, but he said he thought it was likely. "We are trying to keep people who have something to contribute plugged into that public policy switchboard," he added.

The former President will be paid "at top academic scale," according to an AEI spokesman, pro-rated to the amount of time he actually puts in. The salary was not disclosed, but "top academic scale" would be around $40,000, which a Harvard professor earns for approximately a nine-month year.

Baroody said he hoped to sit down with Ford in the next couple of weeks and discuss at length the projects and seminars in which the former President plans to participate.

Ford has accepted several other part-time obligations, including a number of television news appearances on NBC, several lectures at the University of Michigan and positions with the Academy for Educational Development, Inc.