Norwegian aluminium producer Norsk Hydro (NHY.OL) said on Wednesday it was preparing for the global economic downturn to last for another two years, but is hoping for an early recovery.

Sales of building systems products were flat in the final quarter of last year compared with the third quarter because of its strong position in the market, the company told Reuters in an interview.

However, sales of rolled aluminium products, which include packaging for food, fell 11 percent in the final quarter of last year from the third quarter.

Sales of products for the auto sector were hardest hit, down more than 20 percent in the fourth quarter from the third quarter.

(Reporting by Michael Taylor; editing by Peter Blackburn)© Thomson Reuters 2009 All rights reserved