BHP Billiton Ltd has asked a U.S. judge to approve a $50 million settlement of claims that it fraudulently inflated its share price by overstating its ability to manage safety risks before a fatal 2015 dam burst at a Brazilian mine...It would resolve shareholder claims stemming from the Nov. 5, 2015 bursting of the Fundão dam in Minas Gerais...at a mine run by Samarco, a joint venture between BHP and Brazil’s Vale SA...BHP denied wrongdoing in settling with investors...