Saudi Arabia\'s Prince Salman is expected to be named as the defence and aviation minister in the world\'s largest oil exporter, a Saudi source said on Monday. Prince Salman, the governor of Riyadh province, is to be appointed to the post after the death of Crown Prince Sultan earlier in October. The job of defence and aviation minister has long been seen as one of the most important in the conservative Islamic kingdom, which has used multi-billion dollar arms purchases to cement its relations with key allies. Prince Salman, who was born in 1935, is one of the remaining sons of Saudi Arabia\'s founder, King Abdulaziz Ibn Saud, and has been seen as the man next-in-line to rule the kingdom after Crown Prince Nayef, who was made heir to King Abdullah last week. As Riyadh Governor since 1962, he was tasked with the critical roles of overseeing the Saudi capital\'s rapid development and arbitrating disputes between members of the ruling al Saud family. \"He\'s intelligent, political, in touch with the conservative base, but also quite modern minded,\" said a former diplomat to Riyadh interviewed about Saudi Arabia\'s succession process last week. Prince Salman is one of the seven sons born to Ibn Saud by his favourite wife Hassa bint Ahmed al-Sudairi who represent the most powerful bloc within the Al Saud. His full brothers included the late King Fahd and the new crown prince and veteran interior minister, Prince Nayef, and Prince Ahmed, a deputy interior minister.