Tribune Co. approved anti-takeover measures.

The company, owner of the Chicago Tribune, Chicago Cubs and KTLA-TV in Los Angeles, devised a plan by which it can issue additional shares if anyone mounts a tender offer for the company or acquires 20% of its common stock. It will distribute to shareholders the right to buy one new share for every share they already hold. The right to buy these shares only goes into effect after a takeover attempt is started. Tribune said the measure was preventive and it knows of no current efforts to acquire the firm.