MONTREAL - A Quebec judge has abruptly ended an attempt by convicted murderer Valery Fabrikant to sue five former colleagues he claims stole and profited from his research.

A lawyer in the case said Superior Court Justice Nicole Morneau issued a lengthy judgment Monday in which she exercised her right to dismiss proceedings deemed to be frivolous.

Morneau had picked up the case from a fellow judge who had recused himself, but she decided just four days into listening to testimony that Fabrikant's behaviour was too insulting.

"The judge rendered a judgment dismissing his action based on frivolity,'' said Roger Judd Jr., a lawyer for two of the five defendants.

Fabrikant, 67, is serving a life sentence for the murder of four colleagues at Concordia University in 1992.

He was suing five other former colleagues at the university for $600,000 in damages, claiming they "unfairly profited'' from his research and "extorted'' his documents.

The lawsuit was launched just before the killings and had weaved its way through the legal process before arriving at the trial phase this year.

Fabrikant has 30 days to appeal Morneau's ruling.

Laywers for the defendants -- T.S. Sankar, S.Sankar, M.N.S. Swamy, G.D. Xistris and S.V. Hoa -- expressed some relief the legal battles may be nearing an end.

Two of the five still work at Concordia University.

"Finally this nightmare is over that they've been going through for more than 15 years,'' said Judd, who represents the Sankar brothers. "Finally they can go on and live their lives.''

Morneau had just taken over the case from Justice Gilles Hebert, who withdrew about 10 days ago. Hebert said he didn't feel he could be impartial any longer after listening to Fabrikant's rambling arguments and engaging in a number of verbal spats with the plaintiff.

Judd says his clients have spent the better part of two decades battling with Fabrikant, dating back to the time they were all employed at Concordia prior to the quadruple homicide.

"We're closing a very, very sad chapter,'' Judd said.

Despite being declared a vexatious litigator in 2000 for overwhelming the judicial system with motions and requests, Fabrikant was allowed to proceed with the case because it had been filed before the murders.

Judd expects Fabrikant to keep fighting.

"Eventually he'll probably appeal and we'll react at that time,'' Judd said.