A defense contractor now overseen by a former Bush administration cabinet secretary is taking on Halliburton Co. by bidding for one of three Army contracts worth up to $50 billion each to provide food and shelter to U.S. troops in Iraq and Afghanistan.

Within days of former U.S. Treasury Secretary John Snow becoming chairman of the New York hedge fund that owns IAP Worldwide Services Inc., the company submitted its bid for huge Army contracts that will be awarded by year-end.