Montana Supreme Court Justice John Warner has told his colleagues he intends to resign from the state's highest court at the end of the year.

Warner, 66, sent a letter late last week to Chief Justice Mike McGrath saying he intends his last day to be Dec. 31, 2009.

"I've had some health problems," Warner told Lee Newspapers Tuesday. "It's a full-time, high-pressure job. I've got a big family and I want to spend some time with them. It's the time to do that."

Warner announced three years ago that he had non-Hodgkins lymphoma, a kind of cancer that targets the immune system. Warner said Tuesday his health is good, but maintaining it "takes some time out of my day sometimes."

He declined to say if his condition was in remission.

Warner's term would have expired in 2012. His absence now leaves a vacancy for Democratic Gov. Brian Schweitzer to fill.

By law, the governor appoints Supreme Court vacancies from a list of three to five candidates selected by a seven-member Judicial Nomination Commission. The candidates must be lawyers "in good standing," according to the law, because only lawyers may serve as Montana judges.

The selection must be confirmed by the state Senate when the Montana Legislature next meets.

Republican Gov. Judy Martz appointed Warner to the bench in 2003. He replaced Justice Terry Treiweiler, who resigned before the end of his term. Voters overwhelmingly opted to retain Warner in elections in 2004 and 2006.

Serving on the top court was the high end of a more than 40-year career in the law for Warner. A Great Falls, Warner worked at the Anaconda Co.'s Great Falls refinery in his youth before earning a degree at the University of Montana and graduating from law school there in 1967.

Warner worked as Montana Supreme Court clerk for a year and then moved to Havre, where he and his wife, Katherine, raised six children and he launched a 20-year career as a lawyer, representing a host of different kinds of clients.

In 1988, he ran for and won a spot as a Havre district judge, a post he held until Martz tapped him for the top court in 2003.

"I just hope that I left things a little better than I found them," Warner said of his legal career. "I hope I've been of service."

Warner said he has enjoyed working on the high court "immensely."

"I will miss the people that I work with; we work well together," he said. "We disagree, of course, sometimes strongly. But we are all very professional. I've found it a very gratifying experience."

Warner said he hopes to stay involved in Montana's legal community in some fashion. By law, retired district court judges may serve as substitute Supreme Court justices, should the need arise. Warner said he would "make myself available."

Aside from spending time with his children and 12 grandchildren, most of whom live in Montana, Warner said he intended to pursue life's other weighty matters.

"There's just too many fish. Something has got to be done about all these fish," he said. "And, of course, we have to keep the ski hills in business."