JEDDAH, Saudi Arabia, Nov 16 (Reuters) - A prominent half-brother of Saudi Arabia's King Abdullah has resigned from the Allegiance Council, the body responsible for overseeing succession in the world's top oil exporter, according to his website.
Prince Talal bin Abdulaziz, father of billionaire Alwaleed bin Talal, is considered one of the most vocal supporters of reform in the ruling Al Saud family.
His resignation comes three weeks after Prince Nayef, perceived as a conservative who has blocked reforms in the past, was named heir to the throne.
Prince Talal's website gave no reason for his resignation. "After informing King Abdullah, Prince Talal bin Abdulaziz announced his resignation from the Allegiance Council," it said on Wednesday.
His resignation means one of his sons might take his position in the council.
The Allegiance Council was created by King Abdullah five years ago to represent each branch of the Al Saud family in the selection of future heirs to the throne.
In 2009, Prince Talal objected to the royal court's announcement that Prince Nayef had been promoted to second deputy prime minister, a position that meant he was second in line to the throne. He said the council should have been consulted before the decision was taken.
"I call on the royal court to clarify what is meant by this nomination and that it does not mean that he (Prince Nayef) will become crown prince," Prince Talal said in a faxed statement sent to Reuters in 2009.
Saudi authorities revoked Prince Talal's passport in the early 1960s when he pressed for a constitutional monarchy and allied himself to late Egyptian President Gamal Abdel Nasser, the arch-foe of the Saudi monarchy.
Prince Talal was later allowed to return to the kingdom after toning down his rhetoric.
For more information on how the Allegiance Council works click on (Reporting by Asma Alsharif; Editing by Mahmoud Habboush)