Government efforts to boost output and crack down on hoarding and illegal price hikes will soon see China's oil supply return to normal, AFP reported, citing state media. Gas stations across the country have suffered a drop in supply since October, which was put down to oil giants PetroChina and Sinopec protesting artificially low retail prices. The companies must bear the brunt of selling petrol and diesel cheaply while global crude prices are rising. Following a hike in retail prices, PetroChina and Sinopec have been ordered to expand supply to local refiners and are now running at full capacity. The National Development and Reform Commission has also told local governments to penalize gas station operators who increase prices without authorization. Six independent gas stations have been fined for such practices.