Conversion from U3D to PAR is not supported yet :(

Universal 3D (U3D) is a compressed file format standard for 3D computer graphics data.

The format was defined by a special consortium called 3D Industry Forum that brought together a diverse group of companies and organizations, including Intel, Boeing, HP, Adobe Systems, Bentley Systems, Right Hemisphere and others whose main focus had been the promotional development of 3D graphics for use in various industries, specifically at this time manufacturing as well as construction and industrial plant design. The format was later standardized by Ecma International in August 2005 as ECMA-363.

The goal is a universal standard for three-dimensional data of all kinds, to facilitate data exchange. The consortium promoted also the development of an open source library for facilitating the adoption of the format.

PAR is a CAD format that generates 3D object layouts. Solid Edge, a 3D CAD system from Siemens Digital Industries Software, uses the .par extension for its part files, including their geometric forms, appearance, and structural elements.

The PAR file can be combined with other Solid Edge parts to a single assembly (ASM file).