Forest Laboratories Inc. said Monday it has adopted a shareholder rights plan, also known as a “poison pill,” to stop billionaire investor Carl Icahn from taking a bigger stake in the company. Icahn is the second-largest holder of Forest shares and has recently boosted his stake in the company by about 3 million shares, increasing his stake in the company to 11.2 percent from 9.9 percent. Forest said Icahn has made “rapid open market purchases” since the end of his latest proxy contest with the company. The new shareholder rights plan will go into effect if any investor’s holdings exceed 12 percent of the company’s stock in the next 12 months.
