The appointment of Prince Muqrin as deputy crown prince sets up the former intelligence chief as next in line to the throne of Saudi Arabia, the world's largest oil exporter, once Crown Prince Salman succeeds King Abdullah. The youngest son of Saudi Arabia's founder, the prince is an affable former airforce captain, diplomats say, and is a close friend of his nephew Prince Bandar, the current spy chief, with whom he served in the military. An ally of King Abdullah, Muqrin, whom the Saudi embassy in Washington said was born in 1945, has pledged to continue Abdullah's gradual social and eco**mic reforms.