Acting Harvard Police Chief Lawrence J. Murphy has attended a national bus owners convention to represent a local bus firm whose services he arranges and supervises for the University's Commencement and reunion activities.

Officials at the United Bus Owners of America headquarters in Washington D.C. confirmed yesterday that Murphy represented Cavalier Coach Corporation of Medford at their 1993 convention in Miami.

Sources have told The Crimson that Murphy also attended the 1991 convention, but United Bus Owners officials yesterday said they were unable to confirm that.

Murphy was accompanied to South Florida by Joan Libby, Cavalier's president and owner, according to state records.

There is no competitive bidding for the bus contract, which Cavalier has held for all six years it has existed. Harvard's business is worth more than $100,000 a year to the bus company, according to a source.

Murphy did not return phone calls yesterday. He has repeatedly said that he has made no personal financial gain from Cavalier, and that he does not consider his close ties to the bus company a conflict of interest.

Reached at her home last night, Libby had no comment.

In an interview last month, Murphy acknowledged that he is authorized to sign paychecks for Cavalier employees, and that he holds an American Express corporate card in the name of the bus company.

Murphy also acknowledged that he has a close personal relationship with Libby. The acting chief has spent weekday nights at Libby'sJamaica Plain home, and sources said their trip toFlorida was part of a vacation for the twofriends.

Murphy said last spring that he decides whatbus companies to employ for reunions and how toorganize their schedules.

He reportedly does not sign the actual contractwith the bus company.

The University's contract with Cavalier is oneof many long-term relationships, without bid,between Harvard and the companies that provideessential services for the reunions.

Vice President and General Counsel Margaret H.Marshall, who is Murphy's boss, has said she doesnot consider Murphy's relationship to Cavalier aconflict of interest. She did not return a phonecall yesterday.

In interviews in recent weeks, policedepartment employees under Murphy's supervisionreacted angrily to news of the acting chief'sfinancial connections to Cavalier.

Harvard police officers have gone 15 monthswithout a raise, as negotiations for a newcontract have stalled