By Emma Thomasson

BONN, Germany (Reuters) - Grueling talks on forming a post-Taliban government for Afghanistan entered an intense seventh day on Monday as rivals tried to tease out a compromise on a U.N. draft accord to establish an interim administration.

The four Afghan factions represented at the U.N.-sponsored talks in a top-security hotel outside Bonn have agreed on the outline of a power-sharing government.

But they still have to decide on the fine print of an agreement and names for its 29 members.

As the talks continued, U.S. bombers pounded Kandahar, the last bastion of the Taliban in Afghanistan. The U.S. military said the battle for the southern city may be nearing "culmination point."

Fasting during the Muslim holy month of Ramadan like many of the delegates and visibly exhausted, U.N. special envoy Lakhdar Brahimi worked into the early hours with the rival groups in Bonn, discussing proposed changes to a seven-page draft agreement he put to them early on Sunday.

"We are going sentence by sentence, comma by comma. Everybody has comments on every single sentence. There are four groups and four opinions within each group. It is painstakingly tedious," U.N. spokesman Ahmad Fawzi told Reuters.

An adviser to the group backing former King Zahir Shah said they would propose the ex-monarch's close aide Abdul Sattar Sirat to head the interim administration. An adviser to the dominant Northern Alliance said his group had backed the choice.

But Fawzi said the delegates had yet to discuss formally their candidates for the new government around the table and said any discussion of names was only taking place bilaterally.

"We have had no proposals from anyone. They are talking among themselves," he said. "I don't think we'll see the names until tomorrow evening."

DEAL LATER IN WEEK

Western diplomats, always in the wings to remind the Afghans that billions of dollars in reconstruction aid rest on a deal, said haggling over posts could take several more days.

"There is going to be a big fight about all this, starting tonight and going on tomorrow and for a little while," one Western envoy said on Sunday evening. "Quite a lot of people are digging in now. It could even be Thursday or Friday."

Abdul Majid Aziz, adviser to the former king's group, said progress was slow but sure. "We are fighting for the future of Afghanistan. It is not right to put some kind of time constraint that this has to be performed by dawn," he said.

If Rome nominee Sirat were to be approved by all groups at the talks in the Petersberg hotel above the Rhine, he would lead the interim government until the convening of a Loya Jirga, or traditional grand assembly, in about six months.

According to a copy of the U.N. draft proposal obtained by Reuters, the interim authority would be composed of an administration of 29 members, a supreme court and a special independent commission to set up the Loya Jirga.

The draft, which Fawzi said had been amended substantially in the late night talks with Brahimi, proposed an administration made up of a chairman, five deputies and 23 other members.

It also requests the U.N. Security Council to consider mandating an international force to Afghanistan to provide security for Kabul and surrounding areas, and for all participants at the Bonn talks to withdraw forces from the city.

The draft calls for the 87-year-old former king to play a symbolic role in opening the Loya Jirga, which would elect a transitional authority to govern for about 18 months until a constitution is drawn up and a permanent government elected.

REINSTATE 1964 CONSTITUTION

Until then, it suggests that most of Zahir Shah's 1964 constitution -- the most liberal political system the country has ever had -- would be reinstated as Afghanistan's basic law.

Alongside the royalist Rome faction, the second biggest in Bonn after the Northern Alliance, there are two smaller exile groups, the Pakistan-based Peshawar group, and the Cyprus group, both of which can hope to be allocated far fewer government posts.

If Sirat, an ethnic Uzbek and professor of Islamic studies based in Germany who was a minister before the king was deposed in 1973, was confirmed, it would rule out prominent Pashtun tribal leader Hamid Karzai, a widely mentioned candidate.

Northern Alliance Interior Minister Yunis Qanuni and Foreign Minister Abdullah Abdullah are thought likely to keep their posts, although as both are Tajiks one might have to step aside for ethnic balance, diplomats said.

Whether any women would be named in the interim government was still uncertain. The U.N. draft accord calls for government participation for women, whom the Taliban forbade to work, study or leave home without being accompanied by a male relative.