Washington, April 8 (Bloomberg) -- Two House Democrats called for an investigation into the contracts being awarded to rebuild Iraq, including how the Pentagon selected Halliburton Co.'s Kellogg, Brown & Root unit to extinguish oil well fires. Representatives Henry Waxman, of California, and John Dingell, of Michigan, asked the General Accounting Office, the investigative arm of Congress, to review the U.S. Agency for International Development's bidding process for a $1.7 billion rebuilding effort in post-war Iraq. The two lawmakers, in letters to the GAO, say they want a separate probe into whether Halliburton ``received special treatment'' from the Pentagon over...