Shi'ite cleric Hummam Hammoudi says he has been chosen to head the 55-member drafting committee. Mr. Hammoudi is a member of the United Iraqi Alliance, which holds a slim majority in the national assembly.
He said a Kurdish legislator, Fouad Massoum, and a Sunni Arab lawmaker, Adnan al-Janabi, had been chosen to be his deputies.
However, parliament has not formally announced the positions.
The committee will have three months to draw up a permanent constitution acceptable to Iraq's political and religious communities. It will then go to a referendum in October.
Meanwhile, insurgents continued their efforts to disrupt the new government. Officials say a car bomb explosion in central Baghdad killed two civilians and three U.S. soldiers.
Some information for this report provided by Reuters, AP and AP.