A U.S. jury convicted a General Services Administration supervisor yesterday of conspiracy in a case a senior U.S. prosecutor said may mark the end of the five-year corruption scandal that has rocked the agency.

The U.S. District Court jury in Alexandria acquitted defendant Billy Ray Green of eight related counts of bribery and racketeering after 11 hours of deliberations during the past two days.

The case was prosecuted by William Lynch, chief of the Justice Department's GSA task force, which Lynch said is preparing to go out of business after winning nearly 100 convictions or guilty pleas around the country since 1977.

Prosecutors charged Green received a total of $3,000 between 1970 and 1980 from the New York-based United Mineral and Chemical Corp. and two subsidiaries in exchange for inside information about the sale of government stockpiles of mica, a mineral used as an electrical insulator.

A key government witness, former GSA employe Lawrence Commander, earlier pleaded guilty in connection with the case and received a one-year sentence on condition he testify in the case against Green. The maximum penalty for conspiracy is five years in prison and a $10,000 fine.

District Judge Richard L. Williams set sentencing for Green for June 18.