Billionaire Thomas Golisano has set his sights on the Democratic speaker of the Assembly, Sheldon Silver, who may soon bear the brunt of the Rochester Republican’s new political action committee.

Mr. Golisano, a three-time gubernatorial contender who is forming a PAC to spread his wealth to candidates across the state who pledge their support for his movement against Albany’s establishment, is considering bankrolling an effort to topple Mr. Silver, the longest-serving Democratic speaker in state history.

The possibility that one of New York’s wealthiest residents, a sharp-tongued, politically unpredictable businessman who has a history of saturating the state airwaves with his self-financed political ads, may target Mr. Silver has provoked some concern within the speaker’s political operation, according to a knowledgeable source.

The involvement of Mr. Golisano in the 64th Assembly district race has the potential to deprive Mr. Silver of one of his strongest advantages: his overwhelming fund-raising lead over his two primary opponents.

Mr. Golisano’s PAC, which he is expected to announce next week, could finance political ads attacking Mr. Silver and lend a hand to the ground operation of one of his opponents.

A spokesman for Mr. Silver declined to comment.

The speaker, a Lower Manhattan representative who is likely to face a primary for the first time since 1986, has millions of campaign dollars at his disposal and broad name recognition from 32 years of incumbency.

Still, among those critical of Albany’s closed-door process and its cozy relationship with interest groups, Mr. Silver has become a magnet for criticism.

The speaker is not taking any chances. He has hired a prominent political consulting firm to manage his campaign and has tapped the resources of the Working Families Party, a labor-backed group that has endorsed his candidacy.

Mr. Silver is running against a nonprofit organizer, Paul Newell, and a contract lawyer, Luke Henry, although, with the petitioning process yet to be completed, neither candidate is officially on the September ballot.

A campaign aide to Mr. Newell said the candidate has not had any contact with Mr. Golisano but would reach out to him shortly. A spokeswoman for Mr. Henry was not immediately available for comment.

Neither candidate has yet to catch a big-name endorsement. Critics of Mr. Silver have held out hope that Mayor Bloomberg, who has butted heads with the speaker on a number of occasions, would offer his support, but the mayor thus far has stayed out of the race, at least publicly.

Mr. Golisano, who made his fortune from starting a payroll services business, is the founder of the Independence Party, the owner of the Buffalo Sabres, and an active philanthropist.

As an Independence Party candidate, Mr. Golisano ran for governor in 1994, 1998, and 2002. He enlarged his support at each turn but failed to generate enough traction to threaten Governor Pataki seriously, despite having spent nearly $100 million on the three bids. In 2002, he received 14% of the vote, trailing Mr. Pataki by 35 percentage points.

Mr. Golisano combined a platform of cutting taxes, spending, and regulations with a broader indictment of the pay-to-play culture in Albany and the outsize power of interest groups.

Neither at home with Republicans nor with Democrats, he holds views — on drug laws, for example — that show a libertarian streak.

With Mr. Pataki, he found his whipping boy, repeatedly raising allegations of corruption against the former governor. Over the years, the Republican Senate majority leader at the time, Joseph Bruno, tried to win Mr. Golisano over and recruit him to run against Eliot Spitzer in 2006.

Despite coming from a fellow upstater, the overtures never yielded an alliance. Mr. Golisano, while registering as a Republican in 2005, refused to be a cash cow for the Senate conference and opted to sit out the race.

Mr. Golisano’s absence from the gubernatorial race — both as a candidate and a power broker — led to speculation that he was breaking away from politics. Political observers say Mr. Golisano’s PAC is a sign that he is at least keeping the option open of challenging Governor Paterson in 2010.