Highlands and Islands Airports, a Scottish Government Company, is suing Shetland Islands Council.
The two sides agreed a contract in 2005 for the local authority to provide engineering works and other services for a runway extension.
The airport operators accuse the council of not carrying out the work properly, leaving them with a bill for bringing in others to complete the project.
A legal dispute arose because the airport operator raised the action in November 2011 asking a judge to declare the council was in breach of contract. Only later did they try to put a figure of £14,210,000 on their loss. The council claimed that fell outside the time limit the law imposes on damages claims.
Yesterday judge Lady Scott ruled in favour of Highlands and Islands Airports.