Norwegian light metals giant Norsk Hydro AS Tuesday set plans to add another aluminum extruder to its lengthening chain of extrusion operations built up mainly via acquisitions in Europe and the Western Hemisphere in the 90s. The Oslo-headquartered aluminum, magnesium and energy company said it had agreed to purchase Acro, a two-press extruder situated near Sao Paulo, Brazil for an undisclosed sum.

The move came close on the heels of an announcement by Norsk Hydro that it had agreed to buy Rackwitz Aluminium GmbH., an ailing aluminum extruder and smelter in Leipzig, for an undisclosed sum.

Norsk Hydro said it plans to add a third press at the Acro unit, renamed Hydro Aluminium Acro, and have the plan running at 17,000 metric tons a year by next March.

The company's plans for Rackwitz include getting two extrusion presses back in operation some time next year and combining the modestsized smelter with its own facilities in Cleraux in Luxembourg.

Rackwitz resumed operation in January of this year after having been out of action in 1996 during a search for new financing. Norsk Hydro said it expects to have the two-press Leipzig plant running at 12,000 tons a year initially and 15,000 tons a year eventually.