Lee Enterprises Inc. LEE 0.83% said its board has approved a shareholder rights plan, also known as a poison pill, that would prevent hedge fund Alden Global Capital LLC from acquiring more than 10% of the company as it considers Alden’s hostile bid for the newspaper publisher.

The plan will be in effect for a year, the company said Wednesday. Lee Enterprises Chairman Mary Junck said the plan would give the company’s board and its shareholders time to assess the acquisition proposal without undue pressure.

“Consistent with its fiduciary duties, Lee’s Board has taken this action to ensure our shareholders receive fair treatment, full transparency, and protection in connection with Alden’s unsolicited proposal to acquire Lee,” Ms. Junck said in a statement.