With the state comptroller, Alan Hevesi, widely expected to resign his office today under a plea deal, his city counterpart, William Thompson Jr., took his name out of the race to succeed him and another politician, the Bronx president, Adolfo Carrion Jr., emerged as a contender.

For months, Mr. Hevesi has been the subject of an investigation by the Albany district attorney, David Soares, after admitting to using a state driver to chauffeur his ailing wife. Mr. Soares has scheduled a news conference for 12:30 p.m. today, but his office would not confirm reports that a plea deal had been reached.

If the comptroller does not plead guilty to a felony count, he will likely face indictment when a grand jury meets today. Mr. Hevesi’s spokesman, David Neustadt, had no comment yesterday.

Mr. Hevesi has paid the state a total of $206,293.79 since admitting he was wrong not to pay back taxpayers immediately. He won re-election by a wide margin and has previously maintained that the result signaled an affirmation that he should stay in office.

The news of Mr. Hevesi’s possible resignation reignited speculation about his replacement, which would be voted on by the state Legislature, where Democrats have a majority. The most frequently mentioned candidates have been Mr. Thompson, two Democratic assemblymen, Richard Brodsky of Westchester and Thomas DiNapoli of Long Island, a former candidate for state attorney general, Denise O’Donnell of Buffalo, and a businessman, William Mulrow, who lost to Mr. Hevesi in the Democratic primary in 2002.

Mr. Carrion joined that field in recent weeks and is now a serious possibility, a Democratic source said. He is widely expected to run for mayor in 2009, along with Mr. Thompson, who said yesterday he does not want Mr. Hevesi’s job. “I’ve made it clear that I’m very happy as the New York City comptroller, and I’m not interested in the state comptroller position,” Mr. Thompson told reporters yesterday in Lower Manhattan. He praised Mr. Hevesi and said his undoing was “clearly tragic.”

Mr. Carrion’s office issued a statement saying, “The borough president has heard the speculation, but at this point his focus is on serving the citizens of the Bronx.”

Any replacement will likely need the backing of both Governor-elect Spitzer and the Assembly speaker, Sheldon Silver.

Some political analysts said they doubted Mr. Spitzer would select Mr. Carrion, saying he would be better served by picking someone from outside the five boroughs. A close observer of Albany politics, Alan Chartock, said Ms. O’Donnell could be the governor’s best bet. “She’s upstate, she’s Catholic, she’s a woman,” Mr. Chartock said, adding that she’s also “squeaky clean,” which could be important at a time when Albany has been ravaged by investigations of corruption by elected officials.

Just this week, the state Senate majority leader, Joseph Bruno, a Republican, disclosed that he was under federal investigation for his business dealings.

Mr. Brodsky, an ambitious lawmaker who has headed the Assembly’s Committee on Corporations, Authorities, and Commission, could also emerge as a consensus choice, as he is close to Mr. Silver.

Mr. Spitzer would not comment directly on Messrs. Hevesi or Bruno, but he acknowledged there was “an aura of unseemliness” in Albany that his administration would need to address.