Work is expected to start at the Docklands site in May.
Main works will include overlaying the existing runway surface and widening and reinforcement of the taxiways.
Refurbishment of the existing drainage network will also be carried out alongside installation of a new pit and duct network and upgrades to the lighting.
Works will be undertaken outside of airport operating hours to ensure there will be no disruption to flights.
Darren Grover, Chief Operating Officer at London City Airport said: “The runway overlay is a major project, made more complex by the unique location of our runway surrounded by water on three sides.
“I look forward to working with Lagan Construction International to deliver the programme and futureproof the only runway actually in London.”
Steve Turner, Director of International Operations, Lagan Construction International, added: “Having completed projects on over 50 airports across five continents, airport infrastructure works are a core part of our business and our teams are experienced in providing the engineering skills and technologies necessary to deliver both airside and groundside support facilities.
“We look forward to working collaboratively with our client, London City Airport. We have a fully committed team to ensure this contract is delivered with the highest safety standards, low environmental impact, within programme and cost requirements.”
The anticipated completion date of the project is November 2016 and the airport will maintain normal operations throughout the duration of the project.