About 50 Islamic and Christian religious leaders will gather in Vatican today, Timeturk news agency said.
The goal of the conference is to design a joint action plan to reduce tension between the Islamic and Christian religions.
Pope Benedict XVI is expected to speak on 6 November. The attending leaders of the Muslim religion are led by Mustafa Ceric, Grand Mufti of Bosnia (top religious leader).
The conference to last several days will be held behind closed doors.