The agreement was signed between the Portuguese government and wholly-owned Vinci subsidiary Aeroportos de Portugal (ANA).
ANA will invest €650m for the first phase of the existing Lisbon airport extension while around €500m will be spent on the opening of a new civil airport in Montijo.
Roughly €156m will also be provided to compensate the Air Force and to contribute to access works in Humberto Delgado and Montijo.
VINCI Concessions CEO Nicolas Notebaert said: “This project and this investment we are announcing today mark a new confirmation of the two main commitments we took six years ago, when we first applied for the privatisation of ANA to contribute to the development of the Portuguese economy by increasing traffic, and to invest in infrastructure to support future growth.
“Traffic in Lisbon has already increased by almost 100% in the last six years and here we are again announcing new investments after the €200m we have already invested in the different Portuguese airports.”
The latest deal is the result of an agreement by the companies for the main technical, operational and financial assumptions of the project, as well as the evolution of the future economic regulation.
These terms will be incorporated in the addendum to the concession agreement, which will be signed this year upon securing environmental authorisations.
Humberto Delgado and Montijo airports are expected to welcome 48 and 24 air transport movements (ATM) per hour, respectively.
Airports will be able to handle the expected growth of traffic until the end of the concession as part of the dual airport system, which will not change until 2062.