I haven't tried it ... but I believe Cycles was the bridge between Poser and Blender.  There was another one several years ago, but it couldn't keep up with the constant changes that an opensource program goes through.  You might want to check it out quite a few people are using it now.

Cycles is Blender's Open Source Physically Based Render Engine. It is not a bridge between Poser and Blender. Edit: AH! Vaskania beat me to it. :)