Nine members of the Black Hebrews religious sect, including the group's national leader, were found guilty yesterday by a federal jury here of operating an international crime ring that trafficked in millions of dollars worth of stolen airline tickets and used bogus credit cards and worthless checks to purchase hundreds of thousands of dollars worth of merchandise.

The eight-man, three-woman jury returned the verdict after deliberating more than 200 hours over the past 7 1/2 weeks, and two weeks after Chief U.S. District Judge Aubrey N. Robinson Jr. sequestered them amid allegations of jury tampering by government prosecutors. The deliberations made the 89-day trial the longest ever in U.S. District Court here.

The legal defeat for the nine Black Hebrew members came hours after the Israeli Supreme Court dealt a major blow to the status of the 1,500 Black Hebrews in Israel by rejecting the sect's petition that they be allowed to remain in the country.

Although members of the sect, officially known as the Original Hebrew Israelite Nation of Jerusalem, began immigrating to Israel in 1969, they have never been recognized as Jewish and have been denied Israeli citizenship. An attorney for 46 Black Hebrews arrested in Israel in April for working without proper permits and overstaying their visas said the decision could lead to a mass deportation of the sect.

According to testimony during the five-month-long trial here, proceeds of the crime ring were used to support the sect's activity in this country and abroad. Several witnesses testified that many items purchased in the United States with worthless checks and bogus credit cards were taken to Israel and sold on the black market to support the sect's three settlements there.

The Black Hebrews group was founded in Chicago in the late 1960s by Ben Ami Carter, who now heads the sect's settlements in Israel, and traces its origins to the 12 Original Hebrew tribes. Group members consider Israel their homeland, eat only kosher vegetarian foods and observe Saturday as the Sabbath.

The group, which also has settlements in Ghana and Liberia, is estimated by prosecutors and other officials to number between 3,000 and 20,000 members.

Attorneys for the Black Hebrews convicted yesterday said they were reluctant to discuss the case, which for the past three weeks has seen a number of unusual turns, including the dismissal of a juror and the alleged jury tampering.

The attorneys said that both of those actions could be the grounds for appeals. "I'm surprised and sort of disappointed," said defense attorney Joseph Bernard. He echoed statements by other attorneys who said they did not understand how the jury was able to reach its verdict without rehearing tapes from the court-approved wiretaps on telephones in Black Hebrews' residences that were the bulk of the government's case.

U.S. Attorney Joseph E. diGenova, whose office has spearheaded the investigation of the Black Hebrews in this country, said he was "pleased with the verdict" and praised the work of prosecutors J. Michael Hannon, John Stevens and Patrick Coughlin and FBI agents Christopher Kirwan and Keith DeVincentis.

The verdict was the second in eight days involving members of the Black Hebrew sect. Six female members were convicted July 22 of conspiracy and wire fraud in connection with a welfare fraud scheme.

"We consider these verdicts to be a vindication of the investigative process in these important matters," diGenova said. He said he would make no other comment because three other trials involving Black Hebrews are pending as well as "investigations of other matters" involving the sect.

Supporters of the Black Hebrews, including Rep. Mervyn M. Dymally (D-Calif.), have accused the United States and Israeli governments of conspiring against the sect. Dymally testified as a character witness in the trial of the six female Black Hebrews, and said he did not see anything irregular about persons using fraudulent U.S. passports to visit Israel.

Although several of the defendants were convicted of several dozen counts -- ranging from interstate transportation of stolen property and trafficking in stolen property to possession of fraudulent identification documents with the intent to defraud the government -- the prosecution's case centered on the involvement of each of the nine in the operation of the massive crime ring.

Each defendant was convicted of conspiring to operate the crime ring, known in legal terms as a "racketeering influenced and corrupt organization," and participating in its actual operation. The so-called RICO counts carry 20-year prison terms rather than the five-year terms of regular conspiracy and felony charges. On their RICO convictions alone, the defendants face possible 40-year prison terms and fines of $500,000 each.

With the additional counts on which they were convicted, some of the defendants could be sentenced to more than 200 years in jail. However, Robinson said before the trial began that there would be "no life sentences" imposed. He set sentencing for Sept. 15.

Five of the defendants have been jailed since they were arrested in July 1985 and Robinson ordered that they continue to be held. They are national Black Hebrew leader Warren Brown, also known as Prince Asiel; Washington Black Hebrew leader J.C. Vortis; Gerald Bethea; James Stone, and Thomas Cavin.

Robinson also ordered Cordell Debardelaben held without bond.

The other three defendants, Gregory Coles, Darryl Girssom and Kevin E. Robinson, were allowed to remain free until sentencing.

Brown, Bethea and Stone are all from the Chicago area and the other six are from the Washington area.

Vortis and Robinson also are charged in connection with an alleged scheme to charge long distance toll calls to stolen MCI numbers and accounts of other long distance carriers. That trial, which the government last week reduced from 17 defendants to five, is expected to begin in early September.

Attorneys for the Black Hebrews convicted yesterday questioned the government's decision to proceed with the 68-count indictment rather than trimming it to a more manageable length for the jurors.

During their deliberations, the jurors had to weigh the testimony of more than 160 witnesses and thousands of pieces of evidence to reach a total of nearly 400 verdicts.

Juror Ernest Walker of Northwest Washington said yesterday that the 7 1/2 weeks of deliberation were a direct result of the number of decisions the jury had to make.

He said it was especially difficult to weigh the evidence while facing the defendants and their families each day. "I'm really pooped. I'm glad this thing is over," he said.