Syria mediator Brahimi holding talks with Iran and Russia

GENEVA (Reuters) - Syrian mediator Lakhdar Brahimi held talks with Iranian Foreign Minister Mohammad Javad Zarif on Friday on a planned international conference aimed at ending Syria's civil war, Brahimi's spokeswoman said.

"They discussed preparations for 'Geneva 2' in general, not specifically Iran's participation," Khawla Mattar told Reuters in Geneva where they met at the United Nations complex. "They were catching up."

Russian Foreign Minister Sergei Lavrov, who flew to Geneva on Friday to join talks between six major powers and Iran on curbing its nuclear program, was expected to meet Brahimi later in the day or on Saturday, according to diplomats and a source in the Russian delegation to the Iran negotiations.

Russia, an ally of Syrian President Bashar al-Assad, wants Iran to take part in the peace conference but the United States, Saudi Arabia and the main opposition Syrian National Coalition have been against this.

The United Nations hopes the "Geneva 2" conference, which Moscow and Washington are trying to arrange, can convene in mid-December to try to end more than 2-1/2 years of conflict in Syria that has taken more than 100,000 lives.

Russian President Vladimir Putin said on Friday that Western states must persuade the Syrian opposition to attend talks with Assad's government that he said should take place as soon as possible.

Brahimi is to hold "trilateral" talks with Russian deputy foreign ministers Mikhail Bogdanov and Gennady Gatilov, as well as U.S. Under Secretary Wendy Sherman, in Geneva on Monday.

The list of invitees for the Geneva 2 conference as well as participation of the Syrian opposition are on the agenda.

U.N. Secretary-General Ban Ki-moon is expected to announce the conference dates subsequently and send out invitations.

The meeting would seek to build on an agreement reached by world powers in Geneva in June 2012, under the previous mediator Kofi Annan, that calls for a political transition in Syria. But it left open the question of whether Assad would have any role.

(Reporting by Stephanie Nebehay; Editing by Mark Heinrich)