DUBAI/SINGAPORE  - Rising domestic demand and refinery problems have prompted Kuwait Petroleum Corporation (KPC) to delay the loading of some gasoil cargoes, four industry sources said Wednesday. The delays triggered KPC to reschedule some cargoes with one of its biggest customers (PSO), which is contracted to buy around 3 million tonnes of gasoil from KPC in 2012. “KPC rescheduled some cargoes to PSO,” one trader said. “Due to some troubles in secondary units and also due to the current planned shutdown in Mina Al-Ahmadi,” he added.OPEC member Kuwait’s biggest refinery with capacity over 460,000 barrels per day (bpd) is undergoing a planned maintenance since mid-May. The maintenance is expected to last up to 30 days. A KPC source confirmed there were delays due to some problems in secondary refinery units but did not elaborate. “It’s under control now,” he said. KPC, which regularly sells 40,000 to 80,000 tonnes of gasoil a month in the spot market, has not offered any spot cargoes since mid-April, traders said. “There are some delays for end-May to early-June loading cargoes, mainly due to local demand going up for summer,” a second trader with direct knowledge of the matter said. Demand for fuel in the Middle East soars in the summer period due to rising electricity usage with temperatures spiking up.  Gasoil is used for power generation in the Gulf. Pakistan is a major oil products buyer under several term contracts but it enters the spot market during the summer period when agricultural activities pick up and when KPC is unable to supply additional term volumes due to a spike in summer demand.PSO is currently seeking 110,000 tonnes of gasoil for delivery over June and July, its first gasoil spot requirement in more than a year.Bangladesh Petroleum Corporation (BPC) also has a 1.02 million tonne diesel contract with KPC in 2012.