A prisoner from Montgomery County has filed the first of what could be hundreds of appeals for new trials as a result of a ruling by the state Court of Appeals that defendants in jury trials must be present at all discussions of their cases unless they waive that right.

Billy R. Prevatte, the prisoner who asked for retrial in Montgomery County, said in his petition that he was not present at bench conferences held during his January 1978 trial when jurors were questioned about their impartiality. Prevatte is serving two concurrent 30-year prison terms for conspiracy to commit murder and solicitation to commit murder.

Montgomery County State's Attorney Andrew Sonner said the ruling could apply to as many as 100 defendants convicted in the county's Circuit Court alone.

The appeals court ruling, issued last Dec. 28 in a Baltimore case, stated that henceforth the failure of defendants or their attorneys to specifically request the defendant's presence at all stages of a jury trial will be considered a waiver of the right.

But the court said that defendants convicted before the Dec. 28 decision, who are in jail or on parole or probation, should be granted new trials if they can show that their cases were discussed in their absence and that they had not waived their right to be present at those discussions.

Officials differ on what impact the ruling will have.

Deborah Handel, chief of criminal appeals in the Maryland Attorney General's office, said hundreds of prisoners could file petitions requesting new trials under the court's ruling.

Prosecutors "will have to respond to each petition and may have to retry some of the old cases," said Handel, who noted that 100 petitions have been filed in Baltimore. "That could have a terrible impact on the state's time and resources."

"We're potentially talking about a substantial fiscal impact on the prosecutor's and the public defender's offices," Sonner said. He said each petition filed would necessitate at least one day's preparation time by one of his assistants.

Sonner estimated that 300 to 400 of the approximately 10,000 inmates in Maryland prisons would be eligible to petition for new trials under the Court of Appeals decision.

Dene Lusby, chief of inmate services in the Maryland Public Defender's office, said his office does not expect a "high volume" of petitions to be filed. "We expect there will be some new trials granted," Lusby said. "We've already had three month's experience with the ruling and only about 50 petitions have been filed through our office."