China is on an oil-buying spree again. So far in April, China National United Oil Corp., or Chinaoil, the trading unit of state-run China National Petroleum Corp., has bought a total of 19 tankerloads of oil for delivery in June or July, Singapore-based traders said. That is equal to 9.5 million barrels of oil, and is Chinaoil’s largest buying binge on the spot market since October, when it bought 47 cargoes, or 23.5 million barrels, a monthly record for the country. With more than half of April left, Chinaoil could surpass the October total if it keeps buying aggressively. China National Petroleum didn’t immediately respond to an email seeking comment late on Tuesday. Chinaoil’s purchases were made through what traders call the “e-window,” a mechanism operated by Platts, a commodities price-reporting company […]