Help on Collada import material problem

[Raven]

I've imported some Collada files from xsi, all looks good except that it has assigned a separate material to every object even though there are only about 10 materials in the scene. So I have 350 materials that are not instanced.

Is there a way to condense materials by there properties rather than name?

ie Materials Piston 01, Piston 02, Piston 03 etc are all the physically the same material but are all named different, so have each got their own material.

Any help would be great

Thanks.