Export to OBJ - maintain seperate objects?

[mmmster3d]

Hi,

I have a pair of headphones from an .stl file I've imported into Keyshot and I would like to export it out as an obj.

It actually does this quite well, I am going to Maya with it and it imports into Maya just fine (STL file is huge and crashed maya).

Problem now is the entire headphone is now one piece of geometry.  It actually consists of about 6 different materials- is there a way to keep these separate when you export to OBJ from keyshot?  Using Keyshot 5

At first I tried grouping all objects by material into groups.  Then I made 6 different bips each one containg all objects for one material.  I exported all those out as OBJs which I thought was working but then it turned pieces of the headphone into gigantic squares 

I would post pictures but I can't with these.. any help/ guidance appreciated I have tried nPower importer for maya, have tried MOI3d, not sure how else to get this gigantic stl into maya..

Thanks!