Washington ? Jack Abramoff, the lobbyist who spawned a congressional corruption scandal, pleaded guilty Tuesday to three felonies and pledged to cooperate in a criminal probe edging closer to former House Majority Leader Tom DeLay.

“I plead guilty, your honor,” Abramoff said in flat, unemotional tones, accepting a plea bargain that said he had provided lavish trips, golf outings, meals and more to public officials “in exchange for a series of official acts.”

In one case, he reported payments totaling $50,000 to the wife of a congressional aide to help block legislation for a client. The aide worked for DeLay, according to officials who spoke on condition of anonymity.

Public corruption aside, Abramoff admitted defrauding four Indian tribes and other clients, taking millions in kickbacks from a one-time business partner, misusing a charity he had established and failing to pay income taxes on millions of ill-gotten gains.

He is expected to plead guilty to additional charges today in Miami in connection with charges stemming from the purchase of a fleet of boats.

At the Justice Department, officials said they intend to make use of the trove of e-mails and other material in Abramoff’s possession as part of a probe that is believed to be focusing on as many as 20 members of Congress and aides.

“This investigation continues … however long it takes, wherever it leads,” said Alice Fisher, assistant attorney general.

Abramoff faces as much as 11 years in federal prison as well as fines in connection with his guilty pleas on charges of conspiracy, mail fraud and tax evasion. The precise penalty is to be determined in part by the extent of his cooperation with prosecutors. Together with his former business partner, Michael Scanlon, he is expected to face restitution costs of $25 million.