The consortium told Ministers due to adverse weather, specifically wind conditions, the £1.4 billion bridge will not be completed until May 2017.
Since September 2015, downtime caused by the weather has been 15% more than the contractor anticipated.
The bridge deck and cable installation process is particularly sensitive to wind, which increases as the cables used become longer and are installed at a greater height.
-- Advertisement --
Until May, FCBC believed it could mitigate these effects, however bad weather in April and May has resulted in the contractor stating it can no longer achieve the December 2016 target.
Economy Secretary Keith Brown said: "We will continue to work closely with the contractors and I will personally ensure that every pressure and every resource is brought to bear to deliver or even better the revised target date of May 2017.
"Going forward, in order to ensure that this project remains on track, I have implemented enhanced governance procedures from Transport Scotland senior management and will receive twice weekly updates from the project team.
"We have always been ambitious about this project and have always worked towards a deliberately ambitious target. However, It is important to recognise that FCBC still fully expects the project to complete within the timeframe of their contract. This project is not late and there will be no impact on the public purse."
(LM)
