(Reuters) – Russia’s Rosneft has failed to sell oil in a large tender after demanding prepayment in roubles, five trading sources said on Monday, meaning it will need to find ways to divert more crude to buyers in Asia through private deals. Rosneft was unable to award its jumbo tender to sell a total of 6.5 million tonnes of Urals, Siberian Light, Sokol and ESPO Blend oil loading from Russian ports in May-June because there were no bids from buyers, five traders said on Monday. Rosneft did not immediately respond to requests for comment. (Reporting by Reuters; Editing by David Goodman)