Rapidly expanding Gulf carrier Etihad Airways says it and Air France-KLM have agreed to market some of each other's flights as the first stage of a larger strategic alliance.

Alongside the deal announced Monday, Etihad says the Franco-Dutch airline operator is launching a similar codeshare deal for flights between France and Germany with Air Berlin. The United Arab Emirates-based Etihad bought nearly 30 percent of Air Berlin last year.

Codeshare deals, in which passengers can buy a single ticket for multiple airlines, allow carriers to expand their reach without having to operate additional routes.

Etihad says the Air France-KLM codeshare deal is the first phase of a larger partnership that could see the companies team up on frequent flier programs, procurement and maintenance.