A prominent American Muslim activist charged with accepting hundreds of thousands of dollars from Libya in violation of U.S. law and attempting to hide it from the government is scheduled to plead guilty today, court records show.

Abdurahman Alamoudi has agreed to admit guilt to three counts, including one related to the mysterious movement of $340,000 he allegedly received in a London hotel room from a charity funded by the Libyan government, sources familiar with the case said yesterday. The other two counts cover tax violations and lies on his immigration forms, the sources said.

His plea will be limited to the charges on which he was indicted in March, sources said, but court documents to be made public today will trace in rich detail an explosive allegation that Alamoudi made in plea negotiations with prosecutors -- that Libyan leader Moammar Gaddafi plotted to assassinate Crown Prince Abdullah, de facto ruler of Saudi Arabia.

James P. McLoughlin Jr., an attorney for Alamoudi, said yesterday that Alamoudi "deeply regrets" his involvement in the failed plan. "The situation unfolded far beyond any expectations he had,'' McLoughlin said. "He is now and will continue to cooperate with the government.''

If the plea deal is accepted by a federal judge, sources said, Alamoudi faces up to 23 years in prison, including a special enhancement for supporting terrorism. He could have faced life in prison under the original charges.

Alamoudi's account of the plot greatly complicated a key diplomatic initiative by the Bush administration to persuade Gaddafi to renounce terrorism and end his programs to develop weapons of mass destruction. The assassination plan was allegedly hatched at the same time U.S. and British diplomats were negotiating with the Libyans last year.

A Libyan intelligence official in Saudi custody has substantiated Alamoudi's version of the plot, which was uncovered after the alleged participants were arrested by Saudi and Egyptian authorities, according to informed sources.

Sources said the documents to be filed with Alamoudi's plea will trace the plot through global money transfers designed to fund it. The documents will detail meetings between Alamoudi and senior Libyan officials, whose names will be redacted for national security reasons. But sources said Alamoudi has told investigators that last spring and summer he met twice with Gaddafi about the plan.

It is unclear how closely the plot will be linked to the actual charges against Alamoudi, which include violating U.S. law by taking money from a nation designated as a terrorist state, money laundering and lying to officials when he denied ties to a Palestinian militant group declared a terrorist organization by the U.S. government. Law enforcement sources said the $340,000 Alamoudi allegedly accepted from the Libyans was apparently to be used in the plot, though it is not clear precisely how.

Any plea agreement can collapse, even at the last minute, but today's hearing was announced publicly by the U.S. District Court in Alexandria. If the plea goes forward, it will mark a stunning change of fortunes for Alamoudi, 52, a charismatic Muslim activist from Falls Church who has long been known as a pillar of the American Muslim community.

His arrest last September shook the U.S. Muslim community and reverberated through Washington's political elite. As leader of the American Muslim Council, Alamoudi met on occasion with senior Clinton and Bush administration officials. He also helped found the Pentagon's Muslim chaplain program and is particularly well known in the Muslim community of Northern Virginia, where he helped run a number of charities and political groups.

Local Muslim leaders have protested the government's prosecution of Alamoudi, portraying him as a moderate with no ties to radical groups. But prosecutors have sketched a different picture in the indictment, alleging that Alamoudi hid his ties to a top leader of the Islamic Resistance Movement, or Hamas, which has been designated a terrorist organization by the U.S. government.

In plea negotiations, Alamoudi has told investigators that he was recruited by the Libyan government because of his ties to Saudi dissidents opposed to the royal family, sources familiar with his account said. They said Alamoudi maintains that he did not initially realize that the Libyans wanted to assassinate key members of the royal family, thinking that they only wanted to sow dissent inside the kingdom.

Abdurahman Alamoudi has alleged that Libyan leader Moammar Gaddafi plotted to assassinate Crown Prince Abdullah of Saudi Arabia, sources say.