I entered into a civil partnership 5 years ago. We separated 2 years ago without breaking our civil union. I've met someone and we're getting married. Is it true that marriage automatically ends the civil union?

Yes, the marriage of one of the partners, including to a third party, automatically terminates the Civil union (art. 515-7, al. 1 C. civ.). The civil registrar at the place of the ceremony must make a note of the marriage in the margin of the birth certificate (of the ex-partner who has married) and inform the civil registrar or notary who registered the original Civil union declaration (art. 515-7, para. 2 C. civ.). The latter then registers the dissolution of the Civil union and notifies both partners. 
 

Please note: since January 1, 2007, a partner who marries a third party is no longer obliged to inform his or her partner in advance.