Using the new CATIA 5 Translator module from Autodesk Labs you can directly read CATIA V5 models into Inventor 2009.
There are several general-use translators available on the market. But all these translators are very expensive to buy, or quite inconvenient to use as a web service. And in all these translators, the CATIA translator is the most expensive – probably for licensing reasons.
Autodesk has probably found a way around the licensing limitations. The CATIA V5 Translator is available for free for all Inventor and Inventor LT users. You can install and use the CATIA translator to open .CADPart and .CADProduct files in Inventor 2009 – either in the 32-bit or in the 64-bit version.