Riyadh: Saudi Arabia is to announce a major cabinet reshuffle soon as the four-year term for the current council of ministers has expired, an official told AFP on Wednesday.

The term of the cabinet formed on March 22, 2007 expired 21 days ago based on the lunar Islamic calendar followed in the conservative kingdom.

"The government's mandate has expired, but due to the king's absence, the announce of the reshuffle has been delayed," the official said.

King Abdullah Bin Abdul Aziz, who is also the prime minister, returned to Riyadh on February 23, after being away for three months for medical treatment.

"We can expect significant changes of some ministers," said the official, who declined to comment on speculations over replacing Foreign Minister Prince Saud Al Faisal and Oil Minister Ali Al Naimi.

King Abdullah kept the line-up of ministers unchanged when he ascended the throne after the death of his brother King Fahd in 2005.

In February 2009, he appointed new education, justice and information ministers, a new supreme court chief and a new head of the consultative Shura council, along with the nomination of a deputy education minister for women's education.