A federal judge declared a mistrial yesterday in the six-week conspiracy and bribery case against D.C. businessman John B. Clyburn and James E. Baugh, a former high-ranking official at the Department of Housing and Urban Development.

The jury had deliberated since a week ago yesterday. Shortly before noon yesterday, it told U.S. District Judge Joyce Hens Green that "we cannot reach a verdict on any count without doing violence to our individual judgments."

Thomas Dyson, Clyburn's attorney, said his interviews with jurors willing to talk showed that the jury split roughly 8 to 4 for acquittal.

U.S. Attorney Jay B. Stephens said, "We regret the jury was unable to reach a unanimous decision on these criminal charges." He said he would review the case to decide whether to seek another trial.

Yesterday's mistrial follows the acquittal in July of Clyburn and former D.C. Department of Human Services head David E. Rivers on charges that they conspired to steer more than $2 million in contracts to companies owned by Clyburn or his friends.

Both cases are the product of a 1986-87 federal probe of alleged contracting irregularities in the administration of Mayor Marion Barry. Clyburn, who owned a consulting company called Decision Information Systems Corp., is a friend of the mayor's who did extensive business with the federal and District governments.

In the trial that ended yesterday, Clyburn was accused of conspiring with Baugh to win a $400,000 HUD contract in exchange for business help to Baugh's wife, Veatrice.

Prosecutors said that help took the form of a part-time salary at another company Clyburn owned, marketing advice and help in getting a $45,000 contract with the D.C. Department of Employment Services.

In exchange for Clyburn's help for his wife, prosecutors alleged, Baugh helped steer a $400,000 HUD contract to Clyburn's company in late 1986 to do computer work for the Columbus, Ohio, housing authority.

The case was based on more than nine months of FBI wiretaps of Clyburn's office, beginning in May 1986.

Two other cases arising from the probe -- one targeting Clyburn and D.C. businessman Porter Bankhead, and the other targeting former Departmemnt of Human Services workers Michael Davis and Gladys Baxley -- are pending.

Clyburn and Baugh greeted the mistrial with the hope that Stephens would abandon a prosecution begun under former U.S. Attorney Joseph diGenova.

Clyburn said diGenova used him to try to discredit Barry. "They got on my phone to get Barry, and they were shocked to find out that I don't know Barry that well," Clyburn said. DiGenova declined to comment.

"I was absolutely confident there would be an acquittal," Clyburn said. "I'm very surprised and very disappointed."

Baugh said he is innocent of the charges. Any help he gave Clyburn's company, he said, was an effort to aid minority firms competing for HUD contracts.

"All I tried to do was to make sure that it was a level playing field," he said. He was prosecuted, he added, because he was "in the wrong place at the wrong time," when prosecutors were out to get Barry.

Referring to the divided jury, he added: "That to me sends a message. Isn't there some point in time when you say, 'Hey, let's go on to bigger and better things'?"