A senior Iraqi official said on Thursday the government was holding talks with some major insurgent groups that might be nearing a point where a number would join a fight to drive al Qaeda out of Iraq.

Saad Yousif al-Muttalibi, international affairs director at the National Dialogue and Reconciliation Ministry, said the talks were designed to persuade the groups to halt guerrilla warfare against the government and help defeat al Qaeda.

"We've already established links and contacts with major insurgent groups," Muttalibi told the BBC in an interview.

"One of the aims is to join with them into the fight against al Qaeda. We are almost getting there and to join forces to attack al Qaeda to get them out of Iraq," he said.

No Iraqi officials were immediately available to elaborate on Muttalibi's comments.

Insurgents draw support from Iraq's Sunni Arab minority, once dominant under Saddam Hussein.

The western Anbar province has been a hotbed for the insurgency but since last September there has been a mounting power struggle in the area between al Qaeda, which has non-Iraqi Arabs as its leaders, and fellow Sunnis who oppose the group.

Increasing sectarian violence between Sunnis and Iraq's majority Shi'ite Muslim community has become an additional security concern in the country.

Shi'ite Prime Minister Nuri al-Maliki, who heads a coalition government of Shi'ites, Sunnis and Kurds, has ordered a major crackdown against insurgents and sectarian violence in Baghdad.

President Bush is sending about 26,000 more U.S. troops to Iraq, mainly to back the crackdown in Baghdad.

Iraqi Defense Minister Abdel Qader Jassim said on Wednesday the beefing up of the U.S. military presence in Iraq could last for months but was unlikely to extend into 2008.

IRAQI TROOPS

Previous Baghdad crackdowns foundered partly because Iraq failed to provide as many of its own troops as promised.

Jassim told reporters during a visit to London two Iraqi brigades of 4,000-5,000 troops each had arrived in Baghdad and nearby Diyala province and that two more would arrive in the next week or two.

He said the crackdown had succeeded so far in reducing killings by sectarian death squads and criminal gangs.

Maliki's office said U.S. forces had released a senior aide to Shi'ite cleric Moqtada al-Sadr on the orders of the prime minister. Ahmed Shibani had been held for more than two years.

The U.S. military said: "In consultation with (Maliki), and following his request, coalition leaders determined that Sheik Shibani ... could play a potentially important role in helping to moderate extremism and foster reconciliation in Iraq."

Sadr is an anti-U.S. cleric, who is also the leader of the Mehdi Army militia, which Washington has called the greatest threat to security in Iraq.

Shibani's release is likely to boost the standing of Maliki, an Islamist who relies on Sadr for political support. The Sadrist movement holds a quarter of the parliamentary seats in the Shi'ite Alliance. The Sadrists hold several ministries.

Shibani was arrested in the city of Najaf with another 17 Sadr followers on accusations of possessing heavy weapons. Last year, an Iraqi court found no evidence against Shibani and his colleagues but U.S. forces kept him in detention.

Shi'ite officials said Maliki and the Sadrists had had a tense relationship in the past few months, particularly since the launch of the Baghdad crackdown in which Maliki pledged to tackle both Shi'ite and Sunni militants.

"The Sadrists saw the Baghdad plan as against them. The release will put it back on track," said a senior Shi'ite Alliance official. "Maliki will be their favorite again."

U.S. and Iraqi forces have killed or arrested hundreds of Sadr's followers since the crackdown started.

They extended the crackdown into the Sadr City district, a Mehdi Army stronghold, but have met little resistance and U.S. commanders say senior militants appear to have left the capital.