(Adds diplomat, opposition delegate)
GENEVA, Jan 24 (Reuters) - United Nations mediator on Syria Lakhdar Brahimi will meet separately with delegations of the Syrian government and opposition on Friday in Geneva, opposition sources and the United Nations said.
The opposition will not meet with the delegation led by Syrian Foreign Minister Walid al-Moualem until it endorses the Geneva communique of June 30, 2012 calling for a transitional governing body to be established, one opposition delegate said.
"We have asked the U.N. envoy for the regime to sign on to Geneva 1 and we will not meet them until they do so," he told Reuters.
Diplomats say Brahimi had planned to bring the government and opposition delegations together for a joint meeting to start a negotiating process aimed at resolving nearly three years of conflict in Syria.
A Western diplomat and a United Nations source confirmed on Friday that Brahimi would instead hold separate meetings with the delegations.
Opposition delegate Haitham al-Maleh told Reuters: "We have explicitly demanded a written commitment from the regime delegation to accept Geneva 1. Otherwise there will be no direct negotiations."
U.N. spokeswoman Alessandra Velluci later told a news briefing in Geneva: "This process is being shaped at the moment. It has to take time for the preparations. There are no Syrian-Syrian talks at the moment." (Reporting by Khaled Yacoub Oweis, writing by Stephanie Nebehay; editing by Dominic Evans and Mike Collett-White)