DUBAI - The United Arab Emirates ordered 80 Rafale fighter jets on Friday, the largest order ever for the warplane, a multi-billion dollar arms contract that deepens economic and political ties with France.

French President Emmanuel Macron began a two-day trip to the Gulf on Friday, and will also visit Qatar and Saudi Arabia. His visit comes at a time when Gulf Arab states have voiced uncertainty about the United States' focus on the region even as they seek more weapons from their key security ally.

The French leader has forged a good relationship with Abu Dhabi Crown Prince Sheikh Mohammed bin Zayed al-Nahyan (MBZ) with investments flowing between both countries. Paris has a permanent military base in the Emirati capital.

"In addition to the presence of three French military bases on UAE territory, this mutual trust translates into the acquisition of 80 Rafale planes, 12 Caracal helicopters, and associated elements," the French presidency said in a statement after a signing ceremony between MBZ and Macron on the sidelines of the Dubai Expo 2020.

Dassault shares rose 6% on the announcement.

The deal, which could be worth at least $15 billion, is the biggest bulk purchase of the Dassault-made Rafale, other than by the French army, and comes after deals in Greece, Egypt and Croatia this year.

The on-off negotiations for the Rafale fighter jets have been going on for more than a decade with Abu Dhabi publicly rebuffing France's offer to supply 60 Rafale jets in 2011 as "uncompetitive and unworkable." Abu Dhabi already has Mirage warplanes.

Defence sources said the Rafale would replace the Mirage 2000 fleet and is unlikely to displace the American F-35 as the UAE continues to hedge its security with two major suppliers, France and the United States.

(Additional reporting by Tim Hepher; Editing by Tim Hepher, Karishma Singh and David Evans) ((john.irish@thomsonreuters.com; 0033-1 49 49 53 42;))