AIG: American International's President and COO Resigns

Evan Greenberg, president and chief operating officer of American International Group (AIG Quote) -- the world's largest insurer in terms of market value -- has resigned, the company said today.

No reasons were given for the resignation. The stock was slightly up on the day, gaining 2% to $90.13. Greenberg's father, chairman and CEO Maurice Greenberg, had named Evan Greenberg his successor, though the announcement was challenged by some shareholders.