Ayatollah Hakim's brother, Abdel Aziz, has taken over as leader of Sciri.

BBC: News | Who's who in post-Saddam Iraq

He has carried out negotiations with the US and represented Sciri at international meetings, and holds Sciri's only seat on the US-appointed Iraqi Governing Council.

BBC: News | Who's who in post-Saddam Iraq

He took over as the head of SCIRI and began his ascent to power as the Badr Brigades became the bulk of the Iraqi security forces in Iraq's predominantly Shiite south.

CNN: Mourning in Iran and Iraq for dead Shiite leader

The leader of the Supreme Council for the Islamic Revolution in Iraq (Sciri), Ayatollah Muhammad Baqr al-Hakim, was among about 100 people killed in a massive car bombing in the Shia holy city of Najaf in August 2003.

BBC: News | Who's who in post-Saddam Iraq

Mr Sadr's 30-strong block of followers in parliament, which has 275 members, was the largest faction in the ruling Shia alliance and had backed Mr Maliki as prime minister largely to stop the post going to the Supreme Council for Islamic Revolution in Iraq (SCIRI), their bitter rivals in the Shia alliance.

ECONOMIST: The prime minister, Nuri al-Maliki, is ever more embattled