(AP) - Gov. Eliot Spitzer announced Wednesday that he is resigning, completing a spectacular fall from power for a politician whose once-promising career imploded amid allegations that he paid thousands of dollars for high-end prostitutes.

"I look at my time as governor with a sense of what might have been," Spitzer said, with his expressionless wife Silda standing at his side. "There is much more to be done, and I cannot allow my private failings to disrupt the people's work."

Spitzer says his resignation is effective Monday. He will be replaced by Lt. Gov. David Paterson, who will become New York's first black governor.

The scandal erupted two days ago when allegations surfaced that the 48-year-old Spitzer spent thousands of dollars on a call girl at a swanky Washington hotel on the night before Valentine's Day.

Spitzer was more composed Wednesday than he was at his appearance two days ago, when he looked pale, drawn and glassy-eyed. The couple stood quietly Wednesday, inches apart; they never touched as they entered or left the room.

His wife took deep breaths as hundreds of photos were taken at close range. Each of Spitzer's words was accompanied by a rush of camera clicks.

"Over the course of my public life, I've insisted, I think correctly, that people regardless of their position or power take responsibility for their conduct. I can and will ask no less of myself," he said.

The announcement followed two days of furious activity. Calls for his resignation came immediately. Republicans began talking impeachment if he didn't step aside. Meanwhile, Spitzer stayed holed up in his Manhattan apartment, where he was reportedly weighing his options, including waiting to use resignation as a bargaining chip with federal prosecutors to avoid indictment.

U.S. Attorney Michael Garcia just said in statement that "There is no agreement between this Office and Governor Eliot Spitzer, relating to his resignation or any other matter."

Paterson, the soon-to-be governor, was not at the announcement, but he issued a statement in which he said he was "saddened by what we have learned over the past several days."

"It is now time for Albany to get back to work as the people of this state expect from us," said Paterson.

The case involving Spitzer started when banks noticed frequent cash transfers from several accounts and filed suspicious activity reports with the Internal Revenue Service, a law enforcement official told The Associated Press. The accounts were traced back to Spitzer, leading public corruption investigators to open an inquiry.

A law enforcement official said Tuesday that Spitzer had spent tens of thousands of dollars with the call-girl service Emperors Club VIP. Another official said the amount could be as high as $80,000.

Still another law enforcement official said investigators found that during the tryst with a prostitute named Kristen, Spitzer used two rooms at Washington's Mayflower Hotel - one for himself, the other for the call girl. Sometime around 10 p.m., Spitzer sneaked away from his security detail and made his way to her room, the official said.

According to an affidavit, a federal judge approved wiretaps on the escort service's telephone in January and February. FBI agents in Washington had the Mayflower under surveillance when Spitzer was in town, a senior law enforcement official said.

The officials spoke to the AP on condition of anonymity because of the sensitivity of the case.

Spitzer, a first-term Democrat, built his political reputation on rooting out government corruption, and made a name for himself as attorney general as crusader against shady practices and overly generous compensation. He also cracked down on prostitution.

He rode into the governor's office with a historic margin of victory on Jan. 1, 2007, vowing to stamp out corruption in New York government in the same way that he took on Wall Street executives with a vengeance while state attorney general.

His term as governor has been fraught with problems, including an unpopular plan to grant driver's licenses to illegal immigrants and a plot by his aides to smear his main Republican nemesis. The prostitution scandal, some said, was too much to overcome.

Barely known outside of his Harlem political base, Paterson, 53, has been in New York government since his election to the state Senate in 1985. He led the Democratic caucus in the Senate before running with Spitzer as his No. 2.

Though legally blind, Paterson has enough sight in his right eye to walk unaided, recognize people at conversational distance and even read if text is placed close to his face. While Spitzer is renowned for his abrasive style, Paterson has built a reputation as a conciliator.

Republican Senate Leader Joseph Bruno, speaking at a news conference Wednesday morning, called the crisis "unlike any other ever faced in the state's history."

"?[It is] imperative that we join together and do what is best for 19 million people of this state," Bruno said.

Bruno, though the next highest-ranking official, does not become lieutenant governor upon Paterson's ascension to governor. The lieutenant governor's office would remain vacant until the next general election in 2010 under state law. However, whenever Paterson is out of state or if he were to become incapacitated, Bruno would be acting governor.WatchVideo of Spitzer's announcementVideo of Bruno?s comments

ReadSpitzer's Resignation LetterComplete text of Spitzer's resignation speechLt. Gov. Paterson?s comments on Spitzer?s resignationProfileof Lt. Gov. David PatersonReport links Spitzer to prostitution ringNew York State Constitution