Webb, onetime head of CONCACAF
, the soccer governing body for North America and the Caribbean, surrendered his passports and was released on $10 million bond. He will be confined to a home in New York and subject to electronic monitoring.
Edward O'Callaghan, his attorney, did not comment.
Webb -- one of seven ranking soccer officials
arrested in a dawn raid in Switzerland in May -- agreed to be extradited and arrived in New York
on Wednesday, accompanied by FBI agents. The other officials are fighting extradition.
U.S. law enforcement officials told CNN the former Cayman Islands banker immediately began telling authorities what he knows about a 24-year scheme in which FIFA officials allegedly enriched themselves by rigging organization elections and selling marketing and hosting rights to soccer tournaments and World Cup qualifying matches.
His cooperation could set the stage for a scrum among high-ranking soccer officials and others willing to offer information in exchange for leniency, according to U.S. law enforcement officials.
In all, 14 people were indicted in the scheme, which the U.S. Justice Department says involved $150 million in kickbacks. Four have already pleaded guilty but have not been sentenced.
After days of FBI interviews, Webb, 50, appeared in Brooklyn federal court Saturday wearing a dark suit and blue tie. Relatives sat in the front row.
Webb's case is an example of how U.S. prosecutors are using tactics more commonly seen in cases against organized crime syndicates, officials said.
FBI agents hope to use information from those who return first against those higher up in the alleged conspiracy, the law enforcement officials said.
In court documents, U.S. prosecutors allege that among the bribes Webb allegedly received was $1.1 million to award the marketing rights to a Miami based company for the 2012 CONCACAF Gold Cup and Champions league tournament.
Switzerland-based FIFA banned Webb from "football-related activities" after he was indicted in May in the United States. He had been on the governing group's executive committee since May 2012.
CONCACAF dismissed Webb from his post as president of the organization after the FIFA scandal broke.