June 22 (Reuters) - American Airlines Group Inc AAL.O said on Thursday that Qatar Airways, the Gulf country's state-owned airline, had expressed interest in buying a 10 percent stake worth at least $808 million in the No.1 U.S. airline.

Shares of American Airlines rose 5.5 percent to $51.08 in premarket trading.

The news comes just weeks after Qatar was engulfed in a diplomatic row with neighbor Saudi Arabia, which led other nations including Egypt, the United Arab Emirates and Bahrain in cutting ties with Doha.

Qatar Airways indicated that it would buy the stake on the open market, American Airlines said in a regulatory filing. ( http://bit.ly/2tRVFlK )

American said its certificate of incorporation prohibits anyone from acquiring 4.75 percent or more of the company's outstanding stock without advance approval from the board following a written request.

The company's board did not receive any written request from Qatar Airways, American added.

American Airlines also noted that foreign ownership laws limited the total percentage of foreign voting interest in a U.S. company to 24.9 percent.

(Reporting by Rachit Vats in Bengaluru; Editing by Sai Sachin Ravikumar) ((Rachit.Vats@thomsonreuters.com; within U.S. +1 646 223 8780, outside U.S. +91 80 6749 3798; Reuters Messaging: rachit.vats.thomsonreuters.com@reuters.net))