Shares in UK mining company Rio Tinto fell this morning after the Norwegian Government Pension Fund cited environmental reasons for divesting its holding in the company, increasing the relative value of the hostile bid for Rio Tinto made by UK rival BHP Billiton.

Rio Tinto's share price fell 4.03% to 4089p a share as at 10.25 GMT after Norway's ministry of finance said it would exclude the company Rio Tinto from the Government Pension Fund "due to a risk of contributing to severe environmental damage."