State-run company Petroecuador has awarded a tender to buy 18 cargoes of ultra low-sulfur diesel (ULSD) from U.S.-based oil firm Citizens Energy, a trader close to the deal told Reuters on Tuesday. The cargoes, of 240,000 barrels each, will be received in Ecuador starting in June. Ecuador, Latin America's sixth-largest crude producer and the smallest OPEC member, has ramped up tenders to import finished fuels in anticipation of a major overhaul at the 110,000 barrel per day (bpd) Esmeraldas refinery in October. This is the second tender that Petroecuador has awarded to Citizen Energy in recent months, after buying from it four 210,000 barrel cargoes of cutter stock to produce fuel oil that started to be delivered in April.