The ethics adviser to Norway's giant sovereign wealth fund is considering the fund's continued ownership of part of Rio Tinto Group (LSE:RIO). The Wall Street Journal said the adviser, the Council on Ethics, has told Rio Tinto that it is assessing whether Norway should retain its stake in the mining company amid concerns over the impact on the environment from operating in the Brazilian Amazon. Rio Tinto said that the Mineração Rio do Norte (MRN) mine in Brazil is only 22% owned by the group.

A spokesman said: ?While the MRN operation is not managed by Rio Tinto, it has been working to improve its environmental and social performance to meet industry best practice and our expectations as a shareholder?.