Miner Rio Tinto is about to sell a $19.5 billion stake to the Chinese government owned company Chinalco. Rio Tinto will sell $12.3 billion in assets and will rise $7.2 billion by issuing convertible bonds. Rio Tinto is trying to cut massive debt off its balance sheets from the 2007 $38 billion Alcan takeover. The deal is raising concerns because it is the biggest foreign investment a Chinese company has ever made, and Chinalco is a government owned corporation. The deal still needs to be approved by Australian foreign investment regulators.