Fending off an unsolicited takeover by the owner of USA Today and The Indianapolis Star, Chicago's Tribune Publishing has adopted shareholder rights plan, a so-called "poison pill."
Gannett offered to buy Tribune Publishing last month for about $815 million. Tribune rejected the offer last week, saying the price was too low. The company owns the Los Angeles Time, Chicago Tribune and a number of other newspapers.
The plan announced Monday allows existing shareholders to buy preferred stock if a person or group acquires at least 20 percent of its shares.
Gannett called the defensive maneuver "unfortunate."
''Tribune is putting up another roadblock to prevent its stockholders from realizing compelling, immediate and certain cash value for their investment," Gannett said.