For titanium printing by EBM process there is the company 3A (not only titanium): http://www.applicationsadditivesavancees.fr/index.php/fr/
The poly-shape company is quite well equipped (EBM and SLM): http://www.poly-shape.com/
Otherwise SLM only (it seems to me) you have ERPRO: http://www.erpro.fr/
and http://www.asap-koncept.fr/: I don't know but met at a trade fair
Afterwards, if you want to do a test, you have to choose not only the company but also the machine on which you are doing your test. I worked on it a little a year ago, there are (was?) significant differences in mechanical resistance between parts from different machines.
I recommend companies such as poly-shape, Initial, erpro etc. for which it is really the core business.
Depending on your geography, it can be interesting to work with a subcontractor more or less close to you.
for example AFU will be more interesting if you are in Brittany/Normandy
Companies like sculpteo and materialise will not necessarily be in their comfort zone, especially depending on the specificity of your room and your request. I think that Cresilas subcontracts their DMLS parts, so by necessity neither is it interesting (at least for this specific need).