Rupert Murdoch's Twenty-First Century Fox said Time Warner has rejected an offer it made last month to combine the two media and entertainment giants.Twenty-First Century Fox Inc. also said Wednesday in a brief statement that it is not currently in discussions with Time Warner.The New York Times reported that the June bid totaled $80 billion, or $85 in stock and cash for each Time Warner Inc. share. The report cited anonymous sources and said Twenty-First Century Fox would have sold CNN as part of the deal to avoid anti-trust concerns. Its Fox News competes directly with the news network.The Times also said that Murdoch is determined to make a deal.That price amounted to a 25 percent premium to Time Warner's stock price at the time. The Times said Time Warner's board discussed the offer at length and then rejected it, stating that the company was better off remaining independent.A Time Warner representative did not immediately return calls from The Associated Press seeking comment. The New York company's holdings include the pay-cable channel HBO and Warner Bros. studios.Shares of Time Warner jumped more than 15 percent, or $10.81, to $81.82 in premarket trading, while Twenty-First Century Fox climbed 21 cents to $35.40.