Some plugins for SketchUp allow importing of 3Ds Max .obj files to the program so you can work with them and potentially save them to other formats. Without a plugin you are unable to successfully import OBJ files. One of these plugins that add support for OBJ files is called Import OBJ with Materials. During importing you can also choose the option to import without materials, or importing as mesh.
If you do not have access to the Pro version of SketchUp, the only viable alternative will be some 3rd party converters.
Updated: August 8, 2016