The pledge comes from a meeting between representatives of former Prime Minister Ayad Allawi's supporters, the Sadr Movement, the Fadhila Party and a disaffected part of the Dawa Party.

Dawa, the Islamic Supreme Council of Iraq and the Kurdish Coalition make up the ruling government coalition in Baghdad's weakening central government.

IraqSlogger.com, translating an Arabic story in the newspaper Azzaman, says the parties are opposed to Prime Minister Nouri al-Maliki's government and will "support the position of the central government regarding its exclusive right to explore oil fields and sign contracts with foreign companies."

Despite being coalition partners, the Kurds have riled the federal oil minister by moving forward unilaterally on developing their oil sector.

The Kurdistan Regional Government, which controls three northern provinces, has passed its own regional oil law and signed more than 20 oil deals with foreign oil firms to explore and produce oil.

Oil Minister Hussain al-Shahristani calls the moves illegal and threatens to blacklist any company that has signed with the KRG from doing business in the rest of Iraq, where most of the 115 billion barrels of proven reserves are located.

The KRG wants the oil sector governed in a decentralized way, while Baghdad and most Iraqis want it nationalized and controlled by the central authorities.

According to the article, the four parties aligned on the oil deals will also form a new political bloc to oppose the Maliki government.