ImClone Says Icahn Seeking to Boost Stake

ImClone Systems Inc., maker of colon cancer medicine Erbitux, said billionaire investor Carl Icahn was seeking U.S. antitrust clearance to increase his stake in the company to as much as $500 million.

Icahn held almost 5 million shares of ImClone, or almost 6% of those outstanding, as of April 18, an ImClone spokesman said. That holding was worth about $150.6 million at the close of trading Tuesday.

ImClone shares rose 5 cents to $30.16. The company disclosed Icahn’s filing after U.S. markets closed.

New York-based ImClone was at the heart of the Martha Stewart case, in which she was convicted last year of lying to the government about why she sold nearly 4,000 shares of the company’s stock.