Rail services on the route will be suspended from 10 November

The shutdown has been scheduled to run from 10 to 19 November, with buses provided as an alternative.

Network Rail said the work was needed to prepare the route for the potential impact of severe winter weather.

Inverness Chamber of Commerce chief executive, Casia Zajac, said the closure would be an "inconvenience".

Network Rail said buses would be provided during the suspension and Caledonian Sleeper services would be retimed and diverted after Edinburgh to run via Fife to Aberdeen.

Closing the line for nine days will allow us to complete all of this work quickly and efficiently and mean less long-term disruption David Simpson, Network Rail

Network Rail said there would also be an effect on GNER services and it was working closely with First ScotRail and other operators to minimise disruption.

David Simpson, Network Rail route director for Scotland, said the work has been timed to avoid the tourist season.

He said: "This investment and maintenance programme is essential to ensure the continued running of a reliable rail network in the Highlands.

"Closing the line for nine days will allow us to complete all of this work quickly and efficiently and mean less long-term disruption to services compared to a series of closures over several months."

Steve Montgomery, First ScotRail's operations and safety director, said passengers would find some journeys taking longer than normal and should allow more time for travel.

Ms Zajac said disruption further underlined the chamber's call for the A9 to be converted to dual carriageway. Only certain sections of the road in the Highlands are.

She said: "All transport links are important to the Highland economy and this will come as an inconvenience, but I do understand that we have to maintain what needs to be maintained."