i thought:

Berthold Azidenz Grotesk
Din 1451 Std

maybe.

YOu should check out some more of Josef Muller Brockmann, if you dont know him by now, a god on the european design scene. It is indeed akzidenz.

http://www.imagenow.ie/gallery/flash.htm

this site has a lot of his greatest posters on them

I think the image you posted is a little squashed, if you go to week 3 on the link then you will see more posters in the same group.