White House chief of staff Howard H. Baker Jr. yesterday asked communications director John O. Koehler to step down after a week on the job and go to the United States Information Agency, a White House official said.

The request came as part of Baker's review of White House staff members brought in before the departure a week ago of his predecessor, Donald T. Regan.

Koehler could not be reached for comment last night, but the White House official said Baker told Koehler that he is "reorganizing" the staff and that the nature of the position may be changed.

Koehler was chosen for the job amid a bitter contest between First Lady Nancy Reagan and Regan.

The former chief of staff at one point accused Nancy Reagan of rushing the appointment through without the usual checks.

Officials cited Regan's comment about the

First Lady, made at a senior staff meeting, as a remark that angered President Reagan and hastened Regan's departure.

After Koehler's appointment was announced, it was disclosed that he had belonged to a Nazi youth group in his native Germany when he was 10 years old.

Koehler said that government investigators have known about that for years and that it has no relevance to his political views or ability to serve the government.

The White House official said this did not figure in Baker's decision to let Koehler go.

Koehler, 56, a veteran of the Associated Press, retired from the news organization three years ago to become a public relations consultant. One of his principal clients has been the USIA, whose director, Charles Z. Wick, recommended Koehler to succeed Patrick J. Buchanan.

The White House official said a job would be found for Koehler at the USIA.