Saudi Arabia's King Abdullah has appointed former intelligence chief Prince Muqrin bin Abdulaziz second deputy prime minister.
Holders of the postition have gone on in the past to be crown prince and third in line to lead the world's top oil exporter, where the ruling family controls most senior government posts and, in the absence of elections, wields near absolute authority.
Muqrin, who is about 70, headed Saudi intelligence until he was replaced in July, and is the youngest son of the kingdom's founder Abdulaziz ibn Saud.
"His Royal Highness Prince Muqrin bin Abdulaziz al-Saud, adviser and special envoy to the Custodian of the Two Holy Mosques, is appointed second deputy to the prime minister," said a Royal Court decree carried by the state news agency SPA.
Strategically important U.S. ally and the birthplace of Islam, Saudi Arabia faces long-term domestic worries such as growing energy consumption and high youth unemployment, as well as fears about regional instability after the Arab Spring.
The succession beyond King Abdullah, who is nearly 90 and the fifth of Ibn Saud's sons to reign, is a sensitive subject among the al-Saud dynasty's hundreds of princes.