Vitol, the world’s biggest independent oil trading group, is offering Venezuelan crude to Chinese refiners at a discount that’s three times narrower compared to the illicit sales from Venezuela before the ousting of Nicolas Maduro, anonymous traders with knowledge of the development told Bloomberg on Monday. Vitol has recently offered cargoes of Venezuela’s flagship Merey heavy sour crude grade to China at a discount of $5 per barrel to ICE Brent, according to Bloomberg’s sources. This compares with a discount…