LEAD: William S. Sessions going home yesterday after treatment for an ulcer.

He became executive assistant director for administration, making him one of the top three deputies to the Director, William S. Sessions.

William S. Sessions ended his tumultuous tenure with a push against violent crime.

William S. Sessions, who has been the bureau's director since 1987, has been widely credited with making internal reform of the agency a priority.

- William S. Sessions, Director of the Federal Bureau of Investigation.

The director, William S. Sessions, noted that the destruction of data in Government computers was a Federal crime.

But the director, William S. Sessions, said he would have approved the investigations had he been asked.

Few issues have proved more vexing for William S. Sessions, the bureau's director.

William S. Sessions, the F.B.I. director, requested the survey last fall.

William S. Sessions said the agency was investigating criminal fraud at 234 failed institutions.