Cablevision Systems Corp. is close to buying the Long Island newspaper Newsday from Tribune Co. for $650 million, a person with knowledge of the situation said yesterday.

The deal, which could be announced as soon as today, would net Cablevision, a cable TV company also based on Long Island, its first newspaper. It would also provide much-needed cash to Tribune Co., which is struggling under $8.2 billion in debt it took on when it went private last December.

The person familiar with the talks asked to remain anonymous since the discussions were confidential. Spokesmen for both Tribune and Cablevision declined to comment.

News that Cablevision was close to a deal came one day after Rupert Murdoch’s News Corp. rescinded its own $580 million bid, despite assurances from Mr. Murdoch himself just three days earlier that he would prevail over Cablevision within a week.

The Wall Street Journal and Newsday reported on their Web sites earlier yesterday that a deal with Cablevision was close.

News Corp. would have faced regulatory hurdles to owning Newsday since it already owns two New York-area television stations as well as the New York Post, a feisty Manhattan tabloid.

Mr. Murdoch downplayed those concerns Wednesday in a conference call with reporters following the company’s earnings announcement.

News Corp. already has a waiver to rules barring one company from owning a newspaper and television stations in the same city, but it’s not clear how the Federal Communications Commission would have acted on the renewal of the broadcasts licenses for those two stations had News Corp. picked up another New York-area newspaper.