The five-year contract can be renewed for up to 10 more years at a potential value of $683 million.
The Quebec-based companies were initially awarded an interim contract in June 2012.
The work will be carried out at the department's operating base in Trenton, Ont., and facilities operated by L-3 MAS and Avianor in Mirabel, Que.
The fleet of Airbus A310 aircraft are used by the government for VIP transportation, strategic air-to-air refuelling, as well as passenger, freight and medical evacuation transportation.
L-3 MAS, a division of U.S.-based L-3 Communications (NYSE:LLL), will provide overall program management and maintenance support at CFB Trenton, while Avianor will provide heavy and general maintenance, repair and overhaul services from its Mirabel facility.