Former New York City Mayor Rudy Giuliani and aides to former Gov. George E. Pataki were calling key Republican county chairmen across the state Thursday, urging support for Niagara County Chairman Henry F. Wojtaszek as the next head of the state GOP, according to State Sen. George D. Maziarz, R-Newfane.

While most sources say Giuliani is several months away from addressing a potential gubernatorial candidacy in 2010, the former mayor’s new involvement in the machinery of state Republican politics is viewed as the clearest indication yet that he is seriously exploring a run.

“Clearly, I think he is very interested in running for governor,” said Maziarz, who is on the inside of Wojtaszek’s race for chairman.

Maziarz said late Thursday that Giuliani and Pataki allies were urging support for the Niagara County chairman. Two other knowledgeable Republican sources also verified the calls, in an effort they said is designed to blunt recent progress by Wojtaszek’s rival — Manhattan lawyer Edward F. Cox.

Aides to both Giuliani and Pataki did not return phone calls Thursday seeking comment.

But Maziarz confirmed that Giuliani and Pataki confidants are hoping to persuade some county leaders to reverse commitments they have made in recent days to Cox, son-in-law of the late President Richard M. Nixon and a veteran figure in the state party.

Maziarz faulted outgoing Chairman Joseph N. Mondello of Nassau County for “waiting too long” to bow out of the race Monday after Wojtaszek was trying to show deference to his position.

“That put Henry in a catch-up position, but he’s working feverishly,” he said.

Thomas J. Basile, senior adviser to the Cox campaign, said late Thursday that the phone calls are “not helpful” to the process.

“County chairmen will not take kindly to being strong-armed by former elected officials or their staffers trying to influence this process,” Basile said. “It speaks volumes about their motives and Henry’s complete inability to be independent. We need a strong, independent chairman, and the majority of our leaders across the state already agree that Ed is the person to rebuild the party.”

While Cox has claimed support from 41 of the state’s 62 Republican chairmen and about 60 percent of the weighted vote, Wojtaszek achieved exactly what he was looking for Wednesday when Putnam County Republican Chairman Anthony G. Scannapieco Jr. said he was shifting his support from Cox.

“Circumstances changed once Henry announced that he was a candidate for chairman,” Scannapieco said.

Schenectady County Republican Chairman Thomas D. Buchanan also announced support for Wojtaszek on Thursday, bringing to 11 the number of county chairmen supporting him since his announcement Monday.

Erie County Republican Chairman James P. Domagalski said he has received no calls from anybody and remains uncommitted. His neutrality in the race is considered significant because of his long association with Wojtaszek and his strong support of Giuliani in the past.

But Maziarz said Wojtaszek is countering by labeling as “smoke and mirrors” Cox’s assertions that he will tap Manhattan contacts as fundraising sources.

“The real point of contention is the ability to raise money,” Maziarz said. “Ed Cox is saying he has commitments for $1.5 million, but he won’t name who they are. Henry Wojtaszek has raised more in Niagara County than Ed Cox ever has.”