D.C. Police Chief Maurice Turner reassigned yesterday one of his principal subordinates, Inspector Fred Raines, from head of the department's intelligence unit to night supervisor.

The reassignment, which becomes effective Sunday, comes two weeks after Turner learned that Raines had taken three unsubstantiated police intelligence reports involving Mayor Marion Barry to the U.S. Department of Justice last March 31, without first consulting the chief.

Turner, who said last week he might discipline the 14-year veteran for his unauthorized action, had ordered an investigation of Raines' handling of the matter. He said yesterday the investigation is over and he does not plan to take any disciplinary action against Raines.

As night supervisor, Raines will rotate three shifts and represent the chief in the field and respond to major crimes, according to a police spokesman.

Turner said the reassignment of Raines was part of an overall change in assignments for six inspectors, which he said were needed because of the retirement of one inspector and "burn-out factor" of unnamed others.

"I reassign where I think the department needs it," Turner said.

Raines declined to comment on his new assignment.

"That's a punishment," said Gary Hankins, head of the labor committee of the Fraternal Order of Police. "No question. Night supervisors are the only inspectors who work evenings and have no command. Usually what they do is put rookie inspectors in night supervisor slots. It's far from the top of the rung."

Raines said last week he believed he acted properly by going to the Justice Department to seek an outside investigation, if only to show that politically sensitive allegations in the police reports would be checked thoroughly.

Justice declined to get involved, which left the decision with the D.C. police.

The three reports, which were written in 1982 by D.C. police detectives, described unsubstantiated allegations that Barry either used cocaine or was present while others used the drug during a 1981 Christmas party at "This Is It," a 14th Street night club that features nude dancers.

A fourth report, received Sept. 9, 1982, described unsubstantiated allegations that Barry had used cocaine at after-hours bars in the city.

The mayor, who said he attended the Christmas party, has emphatically denied the allegations contained in the reports and said he has never used cocaine.

A two-month inquiry by The Washington Post turned up no evidence that the mayor used cocaine or any other illegal drug.

Turner said he had personally informed Barry of the allegations after he understood that the information was so unsubstantiated that no investigation was warranted.

Turner also said the U.S. attorney's office, which is part of the Justice Department, was aware of at least some allegations involving the mayor and Turner believed that office would pursue any inquiry if they determined it was necessary.

Barry said this week he had asked City Administrator Elijah B. Rogers to work with Turner to decide whether to take action against Raines.

Rogers said yesterday the chief had advised him of his decision and added: "It's his decision. I expect for him to run the department."

Among the other reassignments Turner made yesterday:

* Inspector Max J. Krupo replaces Raines as head of the intelligence unit.

* Inspector Addison L. Davis, the equal employment opportunity officer, has been reassigned to the property division.

* Inspector Martin H. Niverth of the property division will head the fleet management division.

* Inspector Joyce Leland will take over the equal employment opportunity division.

* Inspector Ronald E. Crytzer will head the police training academy.