Iraq's influential Sunni religious leadership on Saturday put the withdrawal of foreign troops from the country as a condition to participate in the constitution-writing process.

Spokesman of the Committee of Muslim Scholars Omar Ragheb revealed it to reporters after Hareth al-Dhari, head of the committee, met with Ashraf Qazi, UN Secretary General Kofi Annan's special envoy in Iraq.

"Qazi asked the committee to take part in drafting the constitution," said Ragheb, adding "we told him that we had conditions and one of them is to reach a consensus with all parties over a timetable for the withdrawal of the foreign troops from Iraq".

Also on Saturday, some 13 Sunni parties which did not participate in the elections in the weekend announced that they had decided "in principle" to take part in drafting a permanent constitution.

They made the announcement following talks organized by Sunni veteran statesman Adnan Pachachi, a former foreign minister and member of the former Iraqi Governing Council.

Drafting a new constitution is among the chief tasks facing the 275-member national assembly, which would come out from Sunday's elections.

Though most Sunnis stayed away from the polls, some Shiite leaders have reached out to the Sunnis and proposed to include them in the decision-making process.