An unnamed source blamed good global prices for the low stocks. "Prices for South Korean gas oil improved to between US$0.60 and US$0.70 per barrel on average over benchmark Singapore gas oil quotes in February, up from US$0.30 to US$0.40 for January cargoes [and] because of [such] good profit margins, we've exported much more cargoes than previously planned for February at the expense of inventories," said the source.

LG-Caltex is a 50-50 JV between the US giant and one of South Korea's largest companies. The company has a refining capacity of around 650,000 barrels per day.