Bill Belichick stunned the New York Jets yesterday when he abruptly resigned as head coach of the team, a job he held for less than a day after Bill Parcells announced his resignation from the same position Monday.

Belichick cited the uncertainty of an impending change of Jets ownership as the reason for stepping down from a job that was guaranteed to him by contract when he became the team's defensive coordinator and assistant head coach three years ago.

"There are a number of obvious uncertainties that would affect the head coach of the team," Belichick said at the Jets' Long Island headquarters during a bizarre news conference called originally to introduce him as the team's next coach.

"I just don't feel at this time that I can lead the Jets with the 100 percent conviction that I need."

Jets President Steve Gutman said Belichick submitted a handwritten resignation note minutes before the news conference began. Parcells also had planned to attend the session for his longtime assistant going back to their days on the New York Giants in the 1980s, but when he heard about the resignation, he did not come into the room.

Gutman said Belichick's original contract addressed the uncertainties of his role under any new owner. He also described Belichick as having "personal turmoil."

The New England Patriots also wanted to speak with Belichick about the vacancy created Monday when Pete Carroll was fired. The team was denied permission by the Jets and the NFL to contact Belichick about the job because he was under contract to the Jets.

The NFL released a statement yesterday, saying the Jets "informed our office that they continue to retain their contractual rights to Bill Belichick despite his announced resignation as Jets head coach. Based upon that information and upon Belichick's contract on file with this office, we have advised our clubs that no club other than the Jets is permitted to speak with Belichick or his representatives about any NFL employment unless further notified by this office."

Belichick earned a $1 million bonus from the Jets last year as an inducement not to speak with other teams about a head coaching job. League sources said yesterday he essentially had hoped to become a "free agent" if Parcells had decided to resign. That would have allowed him more leverage in contract talks with any team interested in his services and the Jets.

One league source indicated that Commissioner Paul Tagliabue eventually might have to settle any dispute between Belichick and the Jets, or any other team that wants him as its coach. In addition to the Jets and Patriots, the Green Bay Packers have a coaching vacancy, and there could be more in the next week, most notably in New Orleans, where Mike Ditka could lose his job.

Other possible candidates for the Jets job are expected to include former Kansas City coach Marty Schottenheimer, St. Louis offensive coordinator Mike Martz, Atlanta offensive line coach Art Shell and University of Miami Coach Butch Davis. Denver offensive coordinator Gary Kubiak said yesterday that he was not interested in the job, though he did speak with the team Monday.

The Jets have been put up for sale by the estate of late owner Leon Hess, who died last May. A decision on a buyer is expected any day now from Goldman Sachs Group Inc., the firm hired by the estate to handle the sale. The two leading candidates are Charles Dolan, head of Cablevision and owner of the Knicks and Rangers, and pharmaceutical heir Robert Johnson IV, with any buyer still subject to approval by a three-quarters majority of team owners.

Belichick was the head coach of the Cleveland Browns from 1991 to 1995 and was fired following a 5-11 season after team owner Art Modell already had announced he was moving the franchise to Baltimore. The relationship between Modell and Belichick deteriorated that season, and Belichick alluded to that yesterday in his decision to resign.

"I've been in situations, and more importantly my family has been in a situation, where I was the head coach of a team in transition," Belichick said. "Frankly, it wasn't a really good experience for me or for them."

Belichick was the Jets coach for one week in February 1997, when Parcells was trying to get out of a contract with the New England Patriots. While the dispute was being resolved, the Jets hired Belichick to coach the team and named Parcells a consultant. Tagliabue eventually intervened, ruling that Parcells could coach the team and that the Patriots would be compensated with four draft choices for losing their coach.

Parcells then took over for Belichick as head coach, though a clause was worked into both coaches' contracts that assured Belichick he would take over if Parcells resigned or was fired.

Along with becoming the new coach after Parcells's resignation, Belichick also was given ultimate power over all football-related decisions. Parcells, who has three years left on his contract, will remain for an undisclosed term as chief operating officer, but had pledged Monday that he would have very little to do with the operation of the team on or off the field.