The U.S. Court of Appeals yesterday upheld the convictions of nine members of the Church of Scientology found guilty in 1979 of participating in a massive criminal conspiracy to plant spies and conduct break-ins and thefts at government offices.

All nine church members, including five once high-ranking members, were sentenced to prison by U.S. District Judge Charles R. Richey. They have been free on bond pending appeals.

In a separate opinion yesterday, the appeals court also reversed a 1979 decision by then chief judge William B. Bryant and upheld a 1977 search of Scientology offices in Washington in which two cartons of documents were seized by law enforcement officials.

Bryant had ruled that the government agents had illegally rummaged through church documents and offices and had ordered that all materials be returned to the church. The appeals court said yesterday, however, that Bryant did not have a basis to support his wholesale rejection of the search.

The appeals court, in its opinion upholding the convictions, also approved a 1977 search of church offices in Los Angeles, which provided the underlying evidence for the government's prosecution of the case. The court rejected the church members' arguments that the search warrant was invalid and that the search itself was so broad that it was illegal.

The court also rejected the Scientologists' argument that Richey should have been disqualified from the case because the extra security measures that he ordered during the proceedings showed he was prejudiced against them.

The appeals court said that the security measures were "entirely reasonable" considering the nature of the charges in the case, actions that were taken against a witness and the fact that a "loaded gun" was found in Scientology headquarters during the Washington search.

The convictions were upheld by appeals court Judges George MacKinnon, Roger Robb and Patricia Wald. The separate opinion upholding the Washington search was written by MacKinnon. Judge Wald, joined by Chief Judge Spotswood W. Robinson III, wrote a separate opinion in the case.

While all three judges upheld the general legality of the Washington search, Wald and Robinson told Bryant that he must review any documents that have not yet been returned to the church since the Washington search, and determine if they were seized illegally. MacKinnon said he would end the case now and not send it back to Bryant.