CATIA supports JT format, so you should be able to export it to universal 3DXML format used by Dassault Systemes.
Convert JT Open CAD 3D model format to Dassault Systems Universal 3D XML document.
We found 2 software records in the database related to .jt to .3dxml file format conversion.
Microsoft Windows software - convert jt to 3dxml on Windows
A PLM/CAD/CAM/CAE software suite
Convert from jt 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 jt to 3dxml. 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 3D product data optimalization software