OSLO, Feb 27 (Reuters) – Norwegian aluminium maker Norsk Hydro has been told by a Brazilian regulator to cut output from its Alunorte alumina refinery by 50 percent until it complies with an order to safeguard the environment, the company said. The cutbacks follow recent claims by Brazilian federal and state prosecutors of a waste spill at one of Alunorte’s bauxite refuse deposits, although Hydro reiterated that it had found no evidence of any such pollution. “While it is too early to determine the size and impact of the resolution, it could potentially have significant operational and financial consequences,” Hydro said in a statement. Alunorte is the world’s largest alumina refinery, transforming bauxite to alumina, which is turned into aluminium at giant smelters.