BAGHDAD, Iraq (AP) – A leading Shiite lawmaker called Thursday for a Shiite federal region, alarming Sunni Arabs who fear they will lose out on oil revenues and complicating efforts to meet a deadline for drafting a constitution within four days.

During a speech to cheering crowds in Najaf, Abdul-Aziz al-Hakim endorsed calls for a federated Iraq, saying federalism was needed “to keep a political balance in the country” after decades of dictatorship under Saddam Hussein.

“We believe that it is necessary to form one territory that includes the south and central Iraq,” al-Hakim said, referring to areas where Shiites form the majority.

“The constitution must allow the formation of regional governments along with the united central government based on the principles of equality and justice,” al-Hakim added. “We must not let this chance to accomplish this goal go away.”

The move could pave the way for a Shiite south and a Kurdish north. The Kurds have demanded federalism to maintain control over three northern provinces and also want authority over Kirkuk, from which thousands of Kurds were expelled by Saddam.

Most of Iraq’s vast oil wealth is concentrated in the Kirkuk area of the north or in the Basra area of the south. Sunnis fear they could lose out on Iraq’s oil riches under a loosely federated system.

Al-Hakim’s maneuvering could also complicate U.S. efforts to produce a constitution that will win the backing of Sunni Arabs in the Oct. 15 referendum and draw them away from the insurgency.

The comments from al-Hakim, leader of the country’s biggest Shiite party, drew a sharp response from Sunni Arab politicians.

“We were surprised with Abdul-Aziz al-Hakim’s declarations today,” said Saleh al-Mutlaq, a member of the constitutional commission. “Time is running out and such declarations should be much more calm. We don’t have time for such maneuvers.”

Ayad al-Samarai, an official of the largest Sunni political group, the Iraqi Islamic Party, said al-Hakim’s remarks also open many side issues – including the distribution of national wealth – which would have to be resolved if the deadline were to be met.

Al-Mutlaq and other Sunnis had suggested that a decision on federalism should be delayed until a new parliament is elected in December. That parliament is expected to have more Sunni Arab members than the current one because many Sunnis boycotted the January election.

Even if the constitution is approved on time, it could face an uncertain fate in the October referendum if large numbers of Sunnis oppose it. Although Sunni Arabs make up only about 20 percent of the population, they form the majority in at least four of the 18 provinces.

If two-thirds of the voters in any three provinces vote against the constitution, it will be defeated under rules set down in the interim constitution.

Chief government spokesman Laith Kubba said the government was eager to promote national unity and rejects “the concept of constructing the government on religious, ethnic and national basis.”

In an Internet statement Thursday, al-Qaida in Iraq, the country’s most feared terrorist group, threatened anyone involved in drafting the “illegal constitution” and vowed to attack voting centers during the October referendum.

“Since the constitution is devoid of religion, those who are writing it and propagating it are renegades,” the statement said. “Therefore the religious court of the al-Qaida in Iraq decided to fight both those who write the constitution or propagate it and to attack referendum centers.”

Al-Hakim’s speech was delivered at ceremonies commemorating the second anniversary of the assassination of his older brother Ayatollah Mohammed Baqir al-Hakim, who died in a huge bombing in Najaf.

Al-Hakim is close to Iraq’s leading Shiite cleric, Grand Ayatollah Ali al-Sistani, who had been reluctant to support federalism. Al-Sistani conferred Wednesday night with al-Hakim and radical Shiite cleric Muqtada al-Sadr in a bid for Shiite unity.

Although al-Sistani has issued no statement about federalism, an official close to the ayatollah said his silence should be interpreted as support. The official spoke on condition of anonymity under rules imposed on the ayatollah’s entourage.

“The Shiite community feels in danger,” the official said. “If Shiites are going to be threatened, they have many cards to play. And if Shiites are going to be sidelined, they will not lie down.”

However, the official said al-Sistani does not support Kurdish claims on Kirkuk.

Government officials said the leadership is trying its best to resolve the issues by Monday’s deadline.

“Every group is saying that they have stands that they cannot abandon because they are ‘red lines’ but in the end, everyone is going to make some concessions,” presidential spokesman Kamran Qaradaghi said. “Meetings are taking place because the political leaders want to reach unanimity and don’t want to sideline any group.”

Insurgent attacks have persisted during the protracted deliberations.

The U.S. military announced Thursday that another U.S. Marine was killed in a roadside bombing the night before in the western city of Ramadi.

More than 40 U.S. soldiers have been killed this month, most of them in bombings. At least 1,842 members of the U.S. military have died since the Iraq war started in March 2003, according to an Associated Press count.