Petroleum Oil Gas:

PetroChina has become the world's largest public oil and gas company at $980 billion according to the Dallas Morning News. Its valuation is four times that of ExxonMobil.

PetroChina ranked 13th in oil equivalent reserves based on 2005 figures. National oil companies occupy the top spots led by Saudi Arabian Oil Company with over 300 billion barrels. Last year PetroChina had 20.5 billion barrels compared to ExxonMobil's 22.1 billion and Royal Dutch Shell's 11.3 billion. For a complete list of the top 50, please see Leading Oil and Gas Companies Around the World.