An election delay could undermine the government and push back the U.S. troop withdrawal, which is supposed to accelerate after the vote. The law has been stalled for weeks as lawmakers argue over how to apportion votes in the oil-rich city of Kirkuk, a city claimed by both Arabs and Kurds.

The head of Iraq's Independent High Electoral Commission, Faraj al-Haidari, earlier this week warned lawmakers that if they did not pass a law by the end of the day Thursday, it would be impossible to carry out the election on Jan. 16, as planned.

On Thursday, before the session ended, al-Haidari reiterated his stance to The Associated Press. But Thursday passed with no vote, and lawmakers said they will meet again Saturday.

Al-Haidari was not immediately available for comment after the session ended. Another commission member, Hamdiyah al-Husseini, said the commission would meet later Thursday to decide how to proceed. She would not comment further.

Iraqi lawmakers have a long history of negotiating down to the wire, and it was unclear whether a compromise was in the offing. One Shiite lawmaker, Bahaa al-Araji, said Thursday that a final version of the election law had been agreed upon by everyone, but that was quickly denied by a Kurdish lawmaker, Massoud al-Sadoon, who said no deal had been finalized.

U.S. officials have been watching the election law debate closely, for any effect it may have on American plans to draw down forces. Under President Barack Obama's plan, all U.S. combat troops will leave Iraq by August 2010. The remaining 50,000 trainers and support troops would go by the end of 2011.

The bulk of the American withdrawal is supposed to come about 60 days after the planned Iraqi election, U.S. commanders have said. U.S. officials have said that they are still hoping the Jan. 16th date will go forward, but say their troop drawdown plan is not set in stone.

Kirkuk has been a source of controversy for decades. Under former dictator Saddam Hussein, tens of thousands of Kurds were forcibly displaced under a plan to make Kirkuk predominantly Arab. After the 2003 U.S.-led invasion of Iraq, many Kurds returned but now other groups claim there are even more Kurds than before Saddam evicted them.

For the Kurds, Kirkuk has a symbolic importance, and they consider it their "Jerusalem." But the Arab-led central government vehemently opposes anything that would remove Kirkuk from its control.

The region is home to vast oil fields, further complicating the issue. A referendum on the city's future, required by the constitution, has been repeatedly postponed.

The immediate question lawmakers have been wrestling with is who will be able to vote in Kirkuk when the election goes forward. Kurds generally have favored using a 2009 voter registry, which likely reflects the Kurdish population growth. Arabs generally prefer a 2004 voter registry, when the Kurdish population was not as large.

Also on Thursday, two people were killed in the central city of Hillah, about 60 miles (95 kilometers) south of Baghdad, when a bomb exploded inside a popular cafe, said Maj. Muthana Khalid, a spokesman for the Babil province police.