D.C. Superior Court Chief Judge Fred B. Ugast, in his first major act as head of the local trial court here, yesterday expanded the number of judges in management positions.

Ugast, who was sworn in last week, also announced appointments to fill vacancies in two key court positions.

Ugast said Judge Robert A. Shuker, appointed in 1977 and a former prosecutor, has been named the presiding judge of the criminal division. Frederick B. Beane Jr., chief deputy clerk of the criminal division for the past 20 years, will take over as the clerk of the court.

Ugast told a morning gathering of the courts' judges that he had created a new deputy position to assist the presiding judges in each of the four divisions of the court to delegate more authority among the judges.

The presiding judges, considered the most important judicial jobs after chief judge, are the chief administrative officers of the divisions.

"I want to get greater participation by more judges . . . " Ugast said later in an interview.

Court officials viewed Ugast's announcement as a sign that the 62-year-old jurist plans to open up the management of the trial court. Although Ugast's predecessor, H. Carl Moultrie I, who died of cancer in April, created the position of presiding judge, he was viewed as holding a tight administrative grip over the court.

"Judge Moultrie did an awful lot himself," said Larry Polansky, the executive officer of the court. "As I read him, Judge Ugast really intends for there to be a much stronger delegation of authority."

Those appointed to the deputy positions were:

Paul R. Webber III, who had been a candidate for chief judge, to civil; Reggie A. Walton, a former prosecutor, to criminal; Bruce S. Mencher, a lawyer formerly in the corporation counsel's office, to family; Virginia L. Riley, a lawyer formerly in private practice, to probate and tax.