Rio Tinto’s chairman-in-waiting resigned from the company’s board on Monday, supposedly in protest at a "Chinese solution" to the mining giant’s US$39 billion debt load, the Wall Street Journal reported. In his resignation statement, Jim Leng merely said there had been "a difference of opinion over which option the company should pursue." People familiar with the situation said Leng had become wary about the possibility of selling minority stakes in some operations to Aluminum Corp of China (Chinalco). Rio Tinto admitted last week that it was in talks with the Chinese company, which already owns 9% of Rio Tinto in partnership with Alcoa of the US. Opponents of a Chinalco deal argue that selling off stakes high-growth assets erodes Rio Tinto’s value in the eyes of investors, while there could be a loss of operational control, depending on how the deal is structured. Rio is also said to be considering an asset sale to Mitsui of Japan.