HONG KONG State-owned oil companies in China and India are trying to buy a Canadian company with oil fields in Kazakhstan in the most direct competition yet for energy between Asia's two most populous countries. A joint venture of China National Petroleum, China's biggest oil company, and PetroChina, its publicly traded subsidiary, offered roughly $3.2 billion late Monday for PetroKazakhstan, a person close to the negotiations said. Oil & Natural Gas, India's main government oil company, has already reportedly submitted a bid of $3.6 billion in cooperation with the steel maker Mittal Group. PetroKazakhstan, whose shares are traded in Toronto,...