Hugh D. Mason III, a D.C. business executive, pleaded guilty yesterday to conspiring to bribe an official of the city's Minority Business Opportunity Commission, saying he gave the official $200 to speed up a firm's certification as a minority contractor and agreed to pay the official for tips about upcoming contracts.

Sources familiar with the case identified the commission official, whose name was not disclosed in court, as Frank S. Borris, a former deputy director.

Borris, who left the commission a year ago and is now a management consultant for the D.C. police department, declined to comment on the case yesterday. His attorney, Anthony Stewart, said, "It appears that Mr. Mason has tricked Assistant U.S. Attorney {David} Eisenberg into giving him a favorable plea agreement in exchange for an unsubstantiated and uncorroborated accusation concerning my client."

Stewart said that in a recent conversation, Eisenberg refused to rule out the possibility that Borris is under an investigation.

As part of the plea bargain, which was sealed, Mason agreed to cooperate with investigators. Eisenberg told U.S. District Judge Stanley Sporkin that the government agreed to drop nine charges of bank fraud, bank larceny and theft contained in a Nov. 4 indictment against Mason, 43. He faces a maximum of seven years in prison and $20,000 in fines.

Mason also pleaded guilty to funneling gratuities to Alexander Exum, the former executive assistant of the D.C. lottery. Exum pleaded guilty in April 1986 to accepting $5,500 in payoffs for lottery contracts, including $500 from Mason.

Mason, in response to Sporkin's questions about the alleged payment to the commission official, said he had paid the money on behalf of a company called Pace Setters Management Inc., which was seeking certification from the commission as a minority-owned firm.

Firms certified by the commission can bid on "sheltered market" contracts, which make up nearly 40 percent of the dollar volume of all D.C. government contracts and are restricted to minority bidders only.

Eisenberg described Pace Setters in court as a successful janitorial supply and maintenance company originally based in New York that opened offices in the Washington area in 1984. Eisenberg said Samuel Lewis, the company's owner, hired Mason after Mason told him he could help the firm obtain contracts.

Mason and Lewis decided to give the commission official $1,000 "to get the {certification} process speeded up" so that the firm could bid on three or four upcoming contracts, Eisenberg said. Lewis has been given immunity in the case, sources said.

Mason told the judge he delivered $200 to the commission official in cash. Sources said Mason kept the remaining $800 because he believed it was owed to him.

Previous grand jury testimony has focused on whether Borris received the full $1,000 from Mason and gave it to his son.

According to Eisenberg, Mason also agreed to pay the official "a percentage" of each contract that the janitorial company received in exchange for information about upcoming contracts.

Commission records show that Pace Setters was certified on Feb. 14, two weeks after the firm applied. The usual processing time is 30 to 90 days.

City records show that Pace Setters received about $114,000 in contracts in fiscal 1985, 1986 and 1987, mainly from the D.C. public schools.