Baghdad ? Former U.S.-backed prime minister Ayad Allawi and his secular, anti-Iranian coalition narrowly won Iraq’s parliamentary elections in final returns Friday, edging out the bloc of Prime Minister Nouri al-Maliki, who angrily vowed to challenge the results.

If Allawi’s coalition remains on top, it will get the first opportunity to form a parliamentary majority and Iraq’s next government, and complete his emergence from what once appeared to be the political graveyard. But they do not automatically mean that he will become prime minister, and the narrow margin sets the stage for months of political wrangling.

A coalition including anti-American cleric Muqtada al-Sadr finished a strong third and could end up playing the role of kingmaker. Kurdish parties also could be crucial in determining who will rule the oil-rich Arab nation of 28 million people.

Allawi told cheering supporters at his Baghdad headquarters he wants to help build a stable region that would help “achieve prosperity for (Iraq’s) people.”

“On this occasion, I’d like to congratulate the Iraqi people and extend the hand of friendship to all neighboring and world countries,” said Allawi, a secular Shiite politician who appealed across sectarian lines to minority Sunnis who have been out of power since the downfall of Saddam Hussein.

Baghdad’s Sunni neighborhoods, the site of vicious sectarian fighting just a few years ago, erupted in cheering, honking of horns and celebratory gunfire in support of the man they have endorsed as their own.

But the results released Friday portend an ugly, protracted battle. No coalition is close to the 163 seats needed to control the 325-seat parliament.

Allawi’s Iraqiya coalition won 91 seats to 89 for al-Maliki’s State of Law bloc. The Iraqi National Alliance, a Shiite religious group dominated by al-Sadr’s followers, won about 70 seats, and Kurdish parties picked up 51.

Regardless of who eventually comes out on top, the results of the March 7 elections suggest that millions of Iraqis are fed up with a political system that revolves around membership in one of the two major Islamic sects.

Iraqiya’s win also shows that many Iraqis are suspicious of Iranian influence. Allawi was widely seen as closer to the region’s Arab governments than to neighboring Shiite Iran.

The next prime minister will lead a government that presumably will be in power when the U.S. completes its scheduled troop withdrawal from Iraq next year. There has been fear among some in the West that a U.S. withdrawal would effectively leave Iraq as an Iranian puppet.

Al-Maliki, the U.S. partner in Iraq for the past four years, announced in a nationally televised news conference that he would not accept the results.

Gesturing angrily, he said he would challenge the vote count through what he described as legal process. By law, he would have until Monday to register his complaints with the election commission.

The prime minister submitted a request to the country’s Supreme Court for clarification on the definition of the biggest bloc in parliament. Under the constitution, the president tasks that bloc with trying to form a government.

In what appears to be a non-binding legal opinion made public Friday, the court left open the possibility that the biggest bloc in parliament could be a coalition formed after the election, not necessarily the biggest coalition as it existed on Election Day. But it was not clear what effect that decision might have and it would be sure to face challenges from Allawi’s followers and others.