Chinese firm buys Rio Tinto stake

SHANGHAI, China -- Alcoa Inc. and Aluminum Corp. of China jointly acquired 12 percent of the shares of London-based global mining company Rio Tinto PLC in a deal believed to be worth $14.05 billion, the companies said Friday. It is the largest overseas investment ever by a Chinese company, Aluminum Corp. of China said, and could very well obstruct a bid from Anglo-Australian mining giant BHP Billiton for Rio Tinto. Alcoa said it contributed $1.2 billion to the total investment.