ALBANY — The Senate Majority Leader, Joseph Bruno, who has run the Republican chamber for more than a dozen years, confirmed today that he won’t seek re-election in the fall.

The 79-year-old Mr. Bruno, considered the oldest serving state legislative leader in the country, has been the state’s top Republican since 2006.

Several Republican senators some of whom could seek the powerful majority leader’s job, refused to comment on Mr. Bruno’s decision, announced in a closed-door session on the last scheduled day of the 2008 legislative session.

Mr. Bruno has been under an FBI investigation for more than a year which appears to be looking at his business associates outside of state government. Mr. Bruno also faced difficult fall elections, not for himself in his district where he is immensely popular, but for his GOP majority which is trying to hold onto the slimmest of majorities in an increasingly Democratic state.

Mr. Bruno’s wife, Barbara, died in January. They had been married more than 50 years.

“Today, I met with my Republican colleagues in the Senate and informed them that I will not be running for re-election this November,” Mr. Bruno said in a prepared statement. “After 32 years in office, I have decided that it is time to move on with my life and to give my constituents an opportunity for new representation and my colleagues in the Senate who have supported me, an opportunity for new leadership.”

Mr. Bruno said he was grateful and felt blessed to be in his role so long.

“I have viewed my work not as a job, but as a privilege to come here day in and day out and stand up for the people of Rensselaer and Saratoga counties and stand up for the hardworking people I have come to know over the years,” Mr. Bruno stated.

“Politics is a tough ball game. Tougher now than it has ever been. But after 32 years of many successes and a few failures, I know now more than ever, and I can say that with comfort and confidence, there is no calling greater than that of public service,” Mr. Bruno stated.

Governor Paterson, a Harlem Democrat who has long had a close relationship with the upstate Republican, told reporters outside the Senate conference room that Mr. Bruno wants to pursue other interests in life.

“I think that it is, in some ways, a sad day for Albany and for me who would like to feel that I have a friendship with him outside of government,” Mr. Paterson said.

Mr. Paterson said he didn’t know if the decision had anything to do with the FBI investigation.

Mr. Paterson said he’s unsure when Mr. Bruno would step down as majority leader. Mr. Bruno’s term ends December 31.

Likely vying for the majority leader’s job, its stipend of more than $30,000 and power as head of the Senate and, likely, head of the state Republican party, include SenatorsThomas Libous of Broome County and Dean Skelos of Long Island. Both hold top deputy positions and have long been considered top candidates.

Their first job: Keeping the Senate majority the Republicans have held for 40 years, but which is now down to a single vote. While Mr. Paterson was the Democratic minority leader, Republicans lost a half-dozen seats even as Messrs. Bruno and Paterson continued to enjoy an almost father-son relationship outside the chamber and a respectful but tenacious relationship on the Senate floor.

Known as a formidable opponent who crippled Governor Spitzer’s administration, the former U.S. Army boxing champion is also one of the most respected and affable of leaders in Albany. His vigor has astounded his critics and supporters as well as Mr. Bruno’s active life that includes boxing workouts, riding his horses, and doing chores at his stables including what he called “mucking out” the stalls.

Months after beating prostate cancer in 2003 and having a torn artery in his stomach surgically repaired in 2004. he was back on the job, in shirt sleeves daily, with aides and reporters decades younger chasing him as he ran up the Capitol’s stairs.

In the spring of 2007, Mr. Bruno was the subject of a front-page story in his district’s dominant newspaper, the Albany Times Union. Travel records had shown Mr. Bruno used state aircraft on days he mixed meetings with lobbyists in Manhattan with GOP fundraisers. The story hinted at potential IRS problems for the perk.

But in a matter of months, Mr. Bruno had turned the story against Mr. Spitzer, accusing his aides of political espionage and misuse of state police. Several investigations followed and although no charges resulted, Mr. Bruno used them to erode Mr. Spitzer’s once historic popularity, force him into politically fatal missteps, and take away any chance of recovery based on his popularity when Mr. Spitzer was named in a federal prostitution investigation. Mr. Spitzer resigned March 17.

Mr. Bruno, who grew up in poverty in Glens Falls north of Albany, worked his way through college and eventually became a top executive in a private telecommunications company. The sale of the company in 1990 and other business dealings had made him a millionaire. He subsequently started a consulting company and dabbled in horse breeding on his sprawling Rensselaer County farm a 25-minute drive from the state Capitol.

The federal probe stemmed from an ongoing inquiry begun in late 2005 by the state Lobbying Commission into the relationship between the Senate leader and an Albany-area businessman, Jared Abbruzzese.

The lobbying commission probe was launched by a former Bruno protege, David Grandeau, who was appointed the commission’s executive director 12 years ago because of Mr. Bruno’s backing. The two subsequently had a falling out.

Mr. Abbruzzese, who contributed more than $70,000 since 2000 to New York Republicans and even more to the national party, but who has also contributed to Democratic presidential candidate Senator Obama, had made corporate jets available to Mr. Bruno and hired him as a consultant. Mr. Abbruzzese’s wife had bought land from a real estate investment company that had ties to Mr. Bruno. Meanwhile, businesses with links to Mr. Abbruzzese received hundreds of thousands of dollars in state funding controlled by Mr. Bruno and Governor Pataki.

There were published reports of Bruno being flown by private jet to Florida where there were visits to race tracks and dinner at a strip club.

On June 3, Albany’s Times Union newspaper reported that the FBI probe had been expanded to also examine Mr. Bruno’s horse-breeding business, particularly the purchase of two horses from a politically well-connected New York real estate developer.

In 2004, Mr. Bruno bought two mares from developer Earle Mack for $50,000 and then spent $74,000 to breed them. The senator later sold three of their foals at auction for $425,000, with Mr. Mack buying one of the offspring for $105,000, the newspaper reported. Mr. Mack is a major contributor to state and national Republican candidates and served as American ambassador to Finland from May 2004 until late 2005. He once served on the board of the New York Racing Association as a Mr. Bruno appointee. NYRA runs the Aqueduct, Belmont and Saratoga thoroughbred tracks.

“I know now more than ever and I can say that with comfort and confidence, there is no calling greater than that of public service,” Mr. Bruno said Monday. “There have been few more rewarding experiences in my life. But, timing in life is everything.

“While there may never be a good time to make these kinds of life decisions, I have decided that it is time for me to move on with my life,” Mr. Bruno said.

“I do so with a heavy heart, but an optimistic soul. And I will rest peaceful in the knowledge that so many great things lie ahead for this great State that I have had the honor and privilege to serve,” Mr. Bruno said.