Catia V4 is a CAD system developed by Dassault Systèmes on 1993. Catia V4 support has ended on 2011.

Catia V4 file extensions are 
.model (Part, Assembly or Drawing)
.exp (export)
.dlv3 (export)
.dlv4 (export)
.session (assembly/overlay of different model files)

Catia V4 supported native or neutral formats are IGES, DXF, STEP, STL.

Dassault Systèmes provides utilities to convert CATIA V4 data files so they are accessible to CATIA V5 and CATIA V6. Still, cases show that there can be issues in the data conversion from CATIA V4 to V5 from either differences in the geometric kernel between CATIA V4 and CATIA V5 or by the modelling methods employed by end users. The percentage loss can be minimized by using the appropriate pre-conversion clean-up, choosing the appropriate conversion options, and clean-up activities after conversion.

For exemple, conversion from CATIA Version 4 to Version 5 created construction problems for the Airbus A380 aircraft. These problems resulted in $6.1B of additional costs due to years of project delays when aircraft wiring was too short to make connections.

CAD Interop distributes several softwares to view, translate and validate Catia V4 files. Find below the list of our solutions compatible with Catia V4: