Franco-Dutch carrier Air France-KLM (AF.FR) has agreed to jointly operate transatlantic routes, sharing revenue and costs, with Delta Airlines Inc. (DAL), of the U.S.

The venture represents about 25% of the industry's total transatlantic capacity and will sharpen the two airlines' ability to compete against other airline alliances, the companies said in a statement Wednesday.

Air France KLM and Delta already work together in the SkyTeam multi-carrier alliance.

Based on 2008-2009 data, the annual joint venture revenue is estimated at $12 billion.

The venture will run more than 200 transatlantic flights and about 50,000 seats daily, they added.

Company Web sites: www.airfrance.com; www.delta.com.

-By A.H. Mooradian, Dow Jones newswires; +33 1 4017 1740; art.mooradian@dowjones.com.