The board of directors at Time Warner Inc. made a change Monday to the company’s bylaws to prevent potential hostile takeovers by dissident shareholders.

The rule change, made public in a Securities and Exchange filing, limits authority to call a special meeting of the shareholders to the only the board chairman, chief executive or a majority of non-employee directors.

Previously, only 15 percent of shareholders were needed to call a special meeting that could be used for voting on a sale of the New York media and entertainment company or attempting a change in the members of the board.

The board’s action is in response to an unsolicited $80 billion bid by media mogul Rupert Murdoch’s News Corp. last week to buy Time Warner, the owner of Warner Bros. Studio in Burbank. The bid was rejected by the Time Warner board.

Shares of Time Warner closed down 58 cents or less than 1 percent to $86.78 on the New York Stock Exchange. The original News Corp. offer was for about $85 a share.