Doh, there were so many other (American) companies that traded with the Nazis. Just the fact that IBM supplied the Nazis with punch-card machines doesn't make them guilty of the killings during the Holocaust.
It was a free market. The fact that IBM had their office in the US doesn't mean that they could not sell their products to other countries, even if they're at war. They sold products to everyone who needed them, so they didn't choose sides. Is that a bad thing?