Delta Air Lines has partnered with Riyadh Air, a startup airline backed by Saudi Arabia's sovereign-wealth fund, to operate flights between the United States and Saudi Arabia. Riyadh Air plans to begin passenger flights next summer as part of the country's plan to diversify its oil-based economy and boost tourism.

Delta and Riyadh did not provide a timeline for the start of flights or financial details of the partnership. The CEOs of both airlines confirmed that neither airline is taking an ownership stake in the other.

Delta CEO Ed Bastian and Riyadh Air CEO Tony Douglas envision selling tickets on each other's flights, a practice known as codesharing, which requires approval from the U.S. Transportation Department. The partnership could potentially evolve into a full-blown joint venture, which would require immunity from U.S. antitrust laws for the carriers to collaborate on prices and share revenue.

Bastian anticipates that the initial traffic will primarily consist of passengers flying to the United States, but expects this to balance out over time as tourism to Saudi Arabia grows. Currently, no U.S. airline flies to Saudi Arabia. The kingdom's flag carrier, Saudia, operates nonstop flights between Saudi Arabia and New York, Dulles International Airport outside Washington, D.C., and Los Angeles.