OSLO, April 16 (Reuters) – The global aluminium market risks facing supply shortages over U.S. sanctions against Russia as well as Norsk Hydro’s production cutbacks in Brazil, Hydro’s chief executive told Reuters on Monday. Industries ranging from automakers to soda-can producers worry over deliveries and sharp price hikes, Svein Richard Brandtzaeg said in an interview. During the weekend, Hydro carried out a 50-percent output reduction at Brazil’s Albras aluminium plant as previously warned, triggered by an unresolved dispute at its nearby Alunorte alumina refinery, which supplies the key raw material. Aluminium prices hit six-year highs on the London Metal Exchange on Monday, continuing a spike that began when the United States imposed sanctions on UC Rusal, the world’s second-biggest producer, as well as Hydro’s own cuts. “There is a shortage of alumina, and there will also be a shortage of aluminium unless Rusal can find new markets quite quickly,” Brandtzaeg said at Hydro’s headquarters in Oslo.