Iraqis have ratified a new constitution with 78 percent voting for it.

Electoral officials announced this on Tuesday, after elections on October 15. The approval paves the way for parliamentary elections, which will be held on December 15.

The biggest support for the constitution comes from Shiites and Kurds, who form nearly 80 percent of the population. Sunni Arabs rejected the constitution, clearly demarcating the vote along ethnic lines.

The constitution would not have been passed if two-thirds of the voters in three provinces had voted against it. Eighteen provinces went to the polls.

Since Sunni Arabs see the constitution as being largely shaped by Shiite and Kurdish interests, American officials have had to broker an agreement with them, allowing for constitutional amendments within the first four months of the new government.

This had led to many Sunni Arab leaders calling for participation in December's elections. While Shittes and Kurds, who are largely located in oil-rich areas, are eager for the creation of autonomous regions, Sunnis fear this.

"Whatever the results of the referendum are, it is a civilised step that aims to put Iraq on the path of true democracy," Farid Ayar, an official with the Independent Electoral Commission of Iraq, said.