OSLO, March 13 (Reuters) – A Norsk Hydro plant’s spill of waste water in Brazil last month was more extensive than previously reported, and the company still lacks overview of the situation, it said on Tuesday.  Authorities in late February ordered Alunorte, the world’s largest alumina refinery, to cut output in half until it addressed pollution concerns, leading Hydro to declare force majeure with no time set to restart production. In addition to a previously reported discharge last month into a local river, a company task force has found that spills also took place from a waste-water pond and from inside the plant into a drain canal, Hydro said in a statement. Separately, a local prosecutor has ordered that the company repair, within 48 hours, cracks in a pipeline and that the drain canal must be sealed off, the company said, adding that it will meet this deadline. “The preliminary findings from the internal task force show that we do not have the full overview of the situation and the course of events,” Hydro Chief Executive Svein Richard Brandtzaeg said. “I will evaluate the situation thoroughly and revert with more information in due time,” he added. By 0907 GMT, Norsk Hydro’s shares fell 0.9 percent. Year-to-date the shares are down 18.6 percent.