The new Forme 10 drydock in Marseille will open for business next week.
The facility, operated by Chantier Naval de Marseille (CNdM), is the biggest dock in the Mediterranean, the company said.
It can handle vessels of more than 270 metres in length due to its measurements of 465 metres by 85 metres.
The first job is maintenance on an MSC cruiseship, which will be followed by two Costa Cruises vessels at the end of November.
Carnival's Costa bought a 33.3% in CNdM last year.
The dock company is also targeting repairs on tankers, cargoships, ro-ros and containerships.
CNdM has been spending EUR 10m ($11.8m) to increase its efficiency.
Work started on the number 10 dock in 2013 and included the construction of a new floating concrete gate, the overhaul of the pumping system and the repair of the lifting facilities.
