GENEVA, Aug 15 (Reuters) - The World Trade Organization (WTO) set up a dispute panel requested on Thursday by China to rule on U.S. safeguard duties imposed on imports of solar cells, a Geneva trade official said.

The decision, automatic upon its second request at a meeting of the WTO's Dispute Settlement Body (DSB), came as the two countries seek a major trade deal to calm simmering tensions.

China charges that the U.S. measure, in the form of a tariff-rate quota on imports of solar cells and an increase in duties on imports of modules, violates WTO rules.

(Reporting by Stephanie Nebehay; editing by John Stonestreet) ((Stephanie.Nebehay@thomsonreuters.com; +41 58 306 2161; Reuters Messaging: stephanie.nebehay.thomsonreuters.com@reuters.net; twitter @StephNebehay))