The agency reorganized itself and strengthened its Los Angeles office by hiring Leonard Pearlstein as president and chief operating officer.

But he added that a review of the process was under way and that the agency had recently reorganized in an attempt to move new systems along.

Dentsu of America in New York said yesterday that there would be a shake-up in top management, effective Jan. 1, as the agency reorganizes under a new name.

The agency has reorganized into three business groups and named three executives as business group directors: Tom James, Larry Riegel and Bill Tucker.

Two agencies have reorganized top management.

Before the agency reorganized its New York office earlier this month, Mr. Guimaraes was one of three group general managers.

Starting in 1992, the agency took over the field management engineering teams that had been assigned to USAF's Major Commands and reorganized them on a functional basis.

Two agencies have reorganized their interactive operations and an interactive agency has named a new president.

A spokesman for the State Office of Mental Health, Robert Spoor, said the agency agreed that the new method was "too complex and confusing" and would reorganize it.

In September 1987 the agency reorganized its New York office into three creative groups and dropped Mr. Ferrell from creative chief to head of a single group.