SPIN BOLDAK, Afghanistan (Reuters) - The most senior Taliban leader held by U.S.-forces in Afghanistan has been freed after helping to broker talks between U.S. officials and Taliban fighters.

A senior foreign ministry official in southern Afghanistan told Reuters Muttawakil had been freed from the U.S. military headquarters at Bagram after helping to arrange talks between U.S. forces and the Taliban in the southern city of Kandahar.

A close friend of Muttawakil said he had been released four days ago. "Now he is living with his family in Kandahar," he said. "I myself have spoken to him by telephone."

Muttawakil, considered a moderate member of the radical Islamic movement, surrendered to Kandahar authorities in February 2002 and was handed over to U.S. forces.

The foreign ministry official, who did not want to be named, said Muttawakil had played "a very important role" in arranging talks between U.S. forces and the Taliban near the airport in Kandahar a few days ago, but declined to give more details.

U.S. military spokesman Colonel Rodney Davis declined to comment on reports of Muttwakil's release. He said he had read a report that Federal Bureau of Investigation officers had met "anti-coalition elements", but could not confirm it.

Taliban intelligence official Mullah Abdul Samad said Muttawakil may have been freed "to sow rifts in Taliban ranks".

Some Taliban officials told Reuters they had reports that the talks may have involved the Taliban's former Interior Minister Mullah Abdul Razzak acting without the consent of the organization's supreme leader Mullah Mohammad Omar.

The news comes a day after the second anniversary of the start of the U.S. intervention in Afghanistan that overthrew the Taliban in late 2001. It also follows an upsurge of Taliban guerrilla activity in recent weeks, with more than 300 people killed since early August including well over 100 militants. "LEAVE, CHANGE OR DIE"

Davis told a news briefing there were three options for militants opposed to U.S.-led forces -- "leave, change or die".

Deputy Secretary of State Richard Armitage visited Kandahar on Sunday but an embassy spokesman said he had not met any Taliban officials.

In Kabul, foreign ministry spokesman Omar Samad said he was still checking the report of Muttawakil's release, but added: "We are pretty sure that that's the case".

At the same time, he said there could be no compromise with militant Taliban who continued to carry out "terrorist" attacks.

The difficulty of completely defeating the Taliban militarily has been underlined by a series of hit-and-run attacks in the south and east of the country in recent weeks which have left the region off limits to most aid workers.

Supreme Court Chief Justice Mawlavi Fazi Hadi Shinwari told Reuters it was government policy to leave the door open for Taliban whose hands were "not tainted with the blood of Muslims".

"We are ready to have negotiations with them and they can come back to the homeland as Afghan citizens," he said.

He said the government had received a list of 30 Taliban members who wished to talk, but declined to give further details.

However, he said the Taliban's former deputy justice minister, Mawlavi Jalaluddin Shinwari, had already joined the government after holding talks in Kabul.

Most top Taliban leaders, including Mullah Omar, have evaded capture. But U.S.-led forces arrested several officials in early 2002, including Mullah Mohammad Chamkani, a former adviser to Omar, and former ambassador to Pakistan Mullah Abdul Salam Zaeef.