The decision came a day after Mr Jaafari, the Shias’ first choice, agreed to step down.
Mr Maliki is the number two in the fundamentalist Dawa party.
He was chosen as their candidate by six of the seven leaders in the United Iraqi Alliance (UIA).
Sunnis back choice
The Sunni-led National Concord Front, one of the main opponents to Prime Minister Jaafari’s candidacy, welcomed the choice of Mr Maliki.
“We welcome the choice of Maliki and believe that we can now form a national unity government in Iraq which will be non-sectarian,” Zhafer al-Ani, National Concord Front spokesman, told AFP.
“We hope that Maliki will be a better leader than his predecessor Ibrahim al-Jaafari,” said Ani, whose group has 44 seats in the 275-member parliament.
Dawa legislator Hassan al-Senaed told AFP that “no other candidacy has been presented and no other faction from the United Iraqi Alliance presented an objection.
“In principle, the UIA will finalise Maliki’s candidacy tomorrow,” Senaed said in reference to an official motion expected to be adopted by the alliance’s 128 members over the weekend.
Maliki’s rival from the Dawa Party, Ali al-Adeeb, who was also named as a possible contender for the premiership, did not mount a challenge at the Shiite leaders’ negotiations on Friday.
Mahmoud Othman, a Kurdish lawmaker, gave a tacit endorsement to Maliki ahead of his nomination.
“Maliki is clearly the frontrunner and there is no objection to his candidacy from any of the parliamentary blocs,” Othman told AFP.
Since the mid-December election for a four-year parliament, Iraqi leaders have been squabbling over the prime minister’s post and ministerial berths amid a dangerous spike in sectarian violence.
The breakthrough came Thursday when Mr Jaafari indicated he was withdrawing his bid for a second term in order to preserve Shiite unity and end the impasse over forming Iraq’s first full-term government since Saddam’s Hussein fall.
“I understand the alliance is facing challenges and I feel that my name should not be associated with issues that delay the nation’s progress,” Mr Jaafari said in a televised address to the nation.
“I do not want to be a hurdle in the democratic process,” he said.
Mr Jaafari was under growing pressure from within the UIA, as well as from other parliamentary blocs and the United States, to stand down in the face of the consistent failure to agree on a cabinet.
Washington is pushing for the quick formation of a broad coalition.
The new government will mark the final phase in Iraq’s political transition since the US-led invasion in 2003 and could pave the way for an eventual withdrawal of US troops.
The main anti-Jaafari lobby was led by the Sunni and the Kurdish blocs in parliament who accused the outgoing premier of monopolising power, and he also faced opposition from secular Shiites.
Iraq’s various parliamentary blocs are currently debating on candidates for the posts of the three-member presidential council, two deputy premiers, one parliament speaker and his two deputies, as well as the prime minister.
On Thursday, Othman said Jalal Talabani was being considered to stay on as president, Shiite Adel Abdel Mahdi to remain as a vice president and Tareq al-Hashemi, a Sunni, as Iraq’s other vice president.
Dulaimi, a Sunni Arab, could become parliament speaker, according to Othman.
US Secretary of State Condoleezza Rice welcomed efforts to break the deadlock.
“It looks like there’s movement and that’s good news,” Rice told reporters.
In violence on the ground, eight Iraqis were killed Friday, including five police commandos, while the US military announced the death of a marine in western Iraq, taking its total death toll since the invasion to 2,384, according to Pentagon figures.