BEIRUT, May 15 (Reuters) - The Lebanese finance minister has asked cabinet to extend the term of central bank governor Riad Salameh which is due expire this summer, a Lebanese government source told Reuters on Monday.

Salameh has been in the post since 1993 and is widely seen as a guarantor of monetary stability.

"The finance minister (Ali Hassan Khalil) sent a letter to the council of ministers asking for the extension of the term of the governor of Banque du Liban by six years," the source said, speaking on condition of anonymity.

"The atmosphere is headed towards approval of the appointment, but it is not certain it will happen this week."

(Reporting by Laila Bassam; Writing by Tom Perry; Editing by Toby Chopra) ((thomas.perry@thomsonreuters.com; Reuters Messaging: thomas.perry.reuters.com@reuters.net))