Icahn says his Apple investment has topped $3 billion

      NEW YORK (AP) - Activist investor Carl Icahn says he has purchased $500 million worth of Apple stock in the past couple of weeks to bring his total holdings in the company to more than $3 billion.

      Icahn disclosed the purchases on his official Twitter account on Wednesday. He also criticized the iPhone and Mac computer maker's board, saying it's doing a "great disservice" to shareholders by not increasing its stock buyback significantly.

      Apple did not immediately respond to a message seeking comment Wednesday morning.

      Icahn has been pushing the company's board to spend more of its cash to repurchase shares.

      Shares of Cupertino, Calf.-based Apple Inc. are up $7.29 at $556.36 in morning trading.