Spc. Ahmed Kousay Altaie, an Iraqi-American serving in the Army Reserve, was abducted in October while he was visiting a relative outside the Green Zone.
Major Gen. William Caldwell, a spokesman for Multinational Force Iraq, said Thursday that Gen. William Casey, the force commander, got permission to post the reward, the Armed Forces Press Service reported.
Caldwell said one coalition soldier has been killed hunting for the missing man, along with two members of the Iraqi security forces. He said more than 300 tips have been received with information.
"We have fairly good information that tells us where we think he could still be held and who perhaps may have him," he said.