CATIA CAD software has the default capability to export its own drawings to common IGES/IGS format. You can also probably achieve the same thing with other CAD programs with support of both formats as well as with some dedicated CAD conversion solution like the CrossManager.
Convert CATIA drawing file to IGES 3D exchange format.
We found 3 software records in the database related to .catdrawing to .igs file format conversion.
Microsoft Windows software - convert catdrawing to igs on Windows
A PLM/CAD/CAM/CAE software suite
Convert from catdrawing file format
The tables with software actions are a good pointer for what a certain program does with various file types and often may give users a good hint how to perform certain file conversion, for example the above-mentioned catdrawing to igs. However, it is not perfect and sometimes can show results which are not really usable because of how certain programs work with files and the possible conversion is thus actually not possible at all.
A CAD converter with huge format support
A 3D CAD translation softwate