As its name suggests, PetroChina Company Ltd is the listed arm of state-owned China National Petroleum Corporation (CNPC). It is China's biggest oil producer, and is listed in Hong Kong, New York, and Shanghai.

Oil price dip eats into profits

This month, the three mainland oil and gas giants - PetroChina, China Petroleum and Chemical (Sinopec) and CNOOC - are expected to report declines in their interim net profits due to lower oil prices.