CAIRO (Reuters) - Syria's opposition and government are preparing to take part in an internationally-sponsored peace conference, the United Nations-Arab League mediator Lakhdar Brahimi said on Tuesday. "The Syrian people are building great hopes on the conference, as the opposition prepares itself to take part and likewise the Syrian regime prepares to take part in this conference," he told reporters at the Arab League. "The United Nations is working to organize the conference in the best way possible." (Reporting by Ayman Samir; Writing by Alexander Dziadosz; Editing by Janet Lawrence)