ABU DHABI (Reuters) - Saudi Arabian Foreign Minister Prince Saud al-Faisal left hospital on Thursday after having an operation, the royal court said.

The 72-year-old prince, a son of the late King Faisal and a nephew of King Abdullah, was appointed in March 1975 and is the world's longest-serving foreign minister.

"His Royal Highness Prince Saud al-Faisal left hospital on Thursday after completing the necessary treatment period and he will spend some time recovering," a brief statement carried by the Saudi Press Agency said.

The agency said on August 11 the prince had had minor surgery to remove an intestinal obstruction caused by a previous operation.

A Saudi dissident group in the United States two weeks later said Prince Saud, who suffers from a chronic back complaint, was critically ill.

But the royal court dismissed the report later that day and said he would be released soon.

(Reporting By Maha El Dahan; Editing by Andrew Heavens)