Senior officials in Iraq's main Shi'ite alliance say the group has selected interim Vice President Ibrahim al-Jaafari as its candidate for prime minister.
Tuesday's announcement came after three days of marathon negotiations, and after another United Iraqi Alliance candidate, Ahmed Chalabi, withdrew his candidacy.
The alliance won 48 percent of the vote in last month's elections, and gained 140 seats in the 275-member National Assembly.
Mr. al-Jaafari, a physician, still faces a challenge from incumbent Prime Minister Iyad Allawi. However, Mr. Allawi's party slate failed to win more than 14 percent of the January 30 vote.
In other developments, a car bomb explosion near an Iraqi troop convoy in Baghdad killed two Iraqi soldiers and wounded more than 20 others.
Some information for this story provided by AP and Reuters.