Mayor Bloomberg, in a move that could help to pave the way for a gubernatorial run, is pushing for Rep. Thomas Reynolds to take the reins of the state Republican Party after he leaves office at the end of the year, sources said.

Along with Governor Pataki, Mr. Bloomberg is attempting to oust the current chairman, Joseph Mondello, 70, who has led the weakened state party for a year and a half from his perch in Nassau County. They want to replace him with Mr. Reynolds, 57, who is retiring from the Buffalo-area seat that he has held since 1999, according to sources. The congressman is said to be weighing his options.

“High-level officeholders, leaders, and elder statesmen have all approached him to be the chairman,” a source close to Mr. Reynolds said. “He’s focusing on his last term in Congress and sorting out what the next chapter in his life is going to be.”

For the mayor, orchestrating new leadership in the party could hand him an advantage if he runs for governor in 2010, giving him a tighter grip on the party’s infrastructure and ensuring a deeper alliance throughout a campaign.

A spokesman for Mr. Mondello said the chairman has been assured by Mr. Reynolds that he’s not eyeing Mr. Mondello’s job.

“As far as we understand, Congressman Reynolds has indicated he is not interested in the position, and we take him at his word,” the spokesman, Anthony Santino, said.

Mr. Bloomberg, an independent who was elected mayor as a Republican, has invested heavily in the state Republican Party through the years and has taken a strong interest in preserving its control of the state Senate.

Republicans have lost two Senate seats under Mr. Mondello’s watch, losing a special election last year in a Nassau district and another special election this year in a district with overwhelmingly Republican enrollment.

Messrs. Pataki and Mondello have had a strained relationship for years, dating back to when the former governor ousted him from a long-held post as a National Republican Committeeman.

The former governor was noticeably absent from the state committee’s annual fund-raising dinner at the Sheraton New York Hotel and Towers last week, at which Vice President Cheney was the guest of honor.

Mr. Mondello was absent last week from a cocktail reception for Senator McCain at a Nassau country club. The fund-raiser was organized by Senator D’Amato and was also attended by Rep. Peter King and the chairman of the New York Conservative Party, Michael Long.

Mr. Reynolds, a former chairman of the National Republican Congressional Committee, was one of the most influential members of Congress before Democrats took over the House in 2006.

A former state assemblyman, he gained a reputation as a savvy legislator and prodigious fund-raiser who had forged deep upstate roots.

But in his last term, after eking out a surprisingly tough victory against a Democratic challenger, Jack Davis, his fortunes dimmed. A scandal involving hundreds of thousands of dollars missing from the Republican Party’s House re-election committee and questions about his handling of sex-related allegations against Rep. Mark Foley of Florida damaged him politically.

The state party has yet to recover since it was battered in the 2006 election that left it shut out from all statewide offices and closer to losing power in the Senate.

Mr. Mondello, a longtime chairman of the Nassau County Republican Party, took over the state party with the blessing of the state Senate majority leader Joseph Bruno, replacing Stephen Minarik, a Pataki appointee who was blamed for the party’s dismal performance.

A spokesman for Mr. Bruno, John McArdle, said the Senate leader stands behind the Republican chairman. “He supports Joe Mondello as chairman, pure and simple,” he said.

State committee aides say Mr. Mondello has stabilized the party’s finances and has reinvigorated the party at the grassroots level. A spokesman said that when Mr. Mondello accepted the job in late 2006, the party did not have enough money to pay a secretary. Now, the committee has amassed close to $1 million, the aide said.

Critics of Mr. Mondello say the party apparatus has atrophied under his leadership. They fault him for spending most of his time in Nassau and for not beating the drums on issues that could energize Republican voters.

More conservative members of party have taken notice of the chairman’s has refrained from attacking Governor Paterson’s recent directive to state agencies that they recognize out-of-state gay marriages.

“If Mondello wants to leave, and Reynolds want to take his place, Reynolds would certainly make a good chairman,” the chairman of the Livingston County Republican Committee, Lowell Conrad, said.