The contractor will work alongside WSP who are supplying design services on the schemes.
The three deals cover highways maintenance management and public realm projects (£30m per year); public lighting maintenance management and mechanical and electrical works (£5.25m per year); and bridge and structures maintenance management and improvement (£2.5m per year).
Each contract is for eight years with an option for a four-year extension and all three start on April 1.
FM Conway has a longstanding relationship with Westminster City Council which has seen it deliver highways services since 1991.
Michael Conway, chief executive officer at FM Conway said: “These maintenance deals demonstrate the scale and quality of our offer and our ability to unlock efficiency savings, drive innovation and recycle materials in our state-of-the-art plants, all key factors in securing the new contracts.
“We have a successful existing partnership with Westminster City Council, and will be working together closely to provide a first-rate service for London’s most iconic infrastructure.”
Chris Dixon, Westminster Contract Director at WSP said: “This is a fantastic win for WSP and FM Conway, which is a result of excellent delivery and client relationships from our existing technical team in Westminster.”