In 2003, a feud developed between Ackman and Carl Icahn over a deal involving Hallwood Realty. They agreed to a "schmuck insurance", under which, if Icahn were to sell the shares within 3 years and made a profit of 10% or more, he and Ackman would split the proceeds. Icahn paid $80 per share. In April 2004, HRPT Property Trust acquired Hallwood, paying $136.16 per share. Under the terms, Icahn owed Ackman Investors about $4.5 million, but refused to pay. Ackman sued. Eight years later, the Court forced Icahn to pay $4.5 million, plus 9% interest per year since the date of the sale.