Offering to outspend Rupert Murdoch and Mort Zuckerman by $70 million to acquire Newsday from Tribune Co., Cablevision Systems Corp (NYSE: CVC). has formally bid $650 million, according to the paper’s sources. The two publishers were being given the chance to up their matching $580 million bids, but AP is reporting now that News Corp (NYSE: NWS) will not go higher. Cablevision is declining comment.

Tribune: “... Tribune Co.‘s informal auction of the newspaper has been surprisingly spirited, considering that newspapers have been suffering through one of the worst advertising recessions in history. Bids have come from “three viable competitors,” each of which would structure its offer to avoid triggering a large capital-gains tax bill for Tribune, said another person familiar with the bidding. Tribune could decide among the offers as early as next week, that person said.”