The upgrade, announced by National Defense Minister Rob Nicholson, will bring the armed forces operational fleet of CP-140s to 14 aircraft.
"Our government is providing the Canadian armed forces with the updated equipment they require, while also ensuring the best value possible for Canadian taxpayers, maximizing job creation, supporting Canadian technological innovation, and bolstering economic growth across the country," Nicholson said.
The Lockheed Martin CP-140 Aurora is based on a P-3 Orion platform and is used by Canada for maritime patrol as well as for intelligence, surveillance and reconnaissance.
Upgrades include new wings and tail and state-of-the-art avionics and missions systems, including the Link 16 Datalink, beyond-line-of-sight satellite communications capability and an improved self-defense system.
The cost of modernizing the four aircraft is about $490.9 million, the government said.
Details on the modernization schedule were not provided.