Top Shiite politicians failed to reach a consensus Wednesday on their nominee for prime minister, shifting the two-man race to a secret ballot and exposing divisions in the winning alliance. In a chilling reminder of challenges facing the winner, a videotape showed a sobbing Italian hostage pleading for her life.

After hours of closed-door meetings, members of the United Iraqi Alliance agreed to hold a secret ballot to choose between Ibrahim al-Jaafari (search) and Ahmad Chalabi (search), most likely on Friday, said Ali Hashim al-Youshaa, one of the alliance's leaders.

The contrast between the two candidates is stark and reveals a division within the clergy-endorsed alliance, made up of 10 major political parties and various allied smaller groups.

Al-Jaafari, 58, is the leader of the religious Dawa Party (search), one of Iraq's oldest parties, known for its popularity and close ties to Iran. Although al-Jaafari is a moderate, his party's platform is conservative.

Chalabi, 58, who left Iraq as a teen, leads the Iraqi National Congress (search) and had close ties to the Pentagon before falling out of favor last year after claims he passed intelligence information to Iran.

A secular Shiite, Chalabi's Iraqi National Congress is an umbrella for groups that included Iraqi exiles, Kurds and Shiites. Much of the intelligence his group supplied on Iraq's alleged weapons of mass destruction (search) programs failed to pan out.

Al-Jaafari was considered the leading contender Wednesday, though Chalabi's aides said their man had enough votes to win.

Both candidates were expected to present their political agendas to alliance members before the secret vote, al-Youshaa said. The 140 lawmakers who will represent the alliance in the National Assembly, plus eight allied lawmakers, will decide who will be prime minister, al-Youshaa said.

A close aide to Grand Ayatollah Ali al-Sistani, the spiritual leader of Iraq's Shiite Muslims, said the alliance's leaders will visit the grand ayatollah's office in Najaf to get his blessing for their choice for prime minister. In the event they can't agree, al-Sistani will make the final decision, said the aide, who spoke on condition of anonymity.

The alliance took 48 percent of the vote in the Jan. 30 national elections, but a two-thirds majority of the assembly is required for the most important decisions, including selection of a prime minister. Kurdish parties, who won 26 percent, have apparently agreed to support the alliance's candidate for prime minister in return for the largely ceremonial presidency.

Sunni Arabs, who were favored under Saddam Hussein's rule, largely stayed away from the polls. But the Shiites must move cautiously if they want to reach out to the Sunnis to form an inclusive government and help quell a violent insurgency.

A U.S. soldier assigned to the 1st Marine Expeditionary Force was killed in action Tuesday in western Iraq, a soldier died of a non-combat injury Wednesday at a base near Tikrit, and four soldiers died in vehicle accidents, the military announced.

In addition, the bodies of eight Iraqis described as collaborators with U.S. forces were found in a desert area north of Baghdad.

The case of the captive Italian journalist took an alarming turn Wednesday, as a videotape delivered anonymously to Associated Press Television News showed Giuliana Sgrena speaking in both French and Italian as she pleaded for the Italian government to withdraw its troops.

"You must end the occupation, it's the only way we can get out of this situation," the 56-year-old journalist for the communist daily Il Manifesto pleaded. There was no indication when the tape was made, and the words "Mujahedeen Without Borders" appeared in digital red Arabic script on the video. The group was previously unknown.

The video was released hours before the Italian Senate voted to extend Italy's troop deployment through June. Il Manifesto strongly opposed the U.S.-led invasion of Iraq and has fiercely criticized Italian Prime Minister Berlusconi's decision to deploy 3,000 troops in the U.S.-led multinational force in Iraq.

At one point Sgrena broke into tears on the videotape, saying: "Show all the pictures I have taken of the Iraqis, of the children hit by the cluster bombs, of the women. ... Help me, help me to demand the withdrawal of the troops, help me spare my life."

Sgrena was kidnapped Feb. 4 by gunmen outside a mosque in Baghdad. Conflicting claims about her fate have appeared on Islamic militant Web sites.

In an interview Tuesday with The Associated Press, al-Jaafari said quelling the violence would be his first priority if he becomes prime minister, and that he would ask U.S. troops to stay as long as they are needed. Despite the Dawa Party's stated desire to impose Islamic law in Iraq, al-Jaafari said he supports guarantees for individual freedoms and women's rights.

Chalabi has promised to cancel contracts the interim government has signed, form a strong intelligence service, and drop charges against Shiite cleric Muqtada al-Sadr, who led two bloody revolts against U.S. forces and is wanted for the murder of a rival cleric, said Ali Faisal of the Shiite Political Council.

Nevertheless, Hayder al-Mousawi, Chalabi's spokesman, said the differences were not a major problem for the Shiite alliance.

"No way is there a division inside the alliance. Everybody agreed on adhering to whatever results the internal elections will reach," he said.

If provisional results of the election stand, the alliance will have 140 seats in the 275-member National Assembly. Al-Youshaa said three other party coalitions, who won a combined eight seats, have joined the alliance bloc.

Farid Ayar, spokesman for the electoral commission, said there have been 25 complaints about the election. "Most of them are asking for a recount of the votes and we are looking into those requests," he said. "You know, they just want more votes."

He said he expected the commission to certify the vote totals Thursday, when the official allocation of seats in the National Assembly would also be announced. The assembly will pick the president, two vice presidents and draft a constitution.

Once results are certified, the present government must set a timetable for installing the new government. There have been no indication how long that might take.