The rail line had been due to open in the summer

The �70m Stirling-Alloa-Kincardine track, which will also take more freight off the roads, was due to open in summer 2007.

A spokesperson for the rail project said the completion date was "under review" to allow extra safety work.

The final cost of the rail line is also expected to increase.

The Scottish Executive had originally earmarked �30m for reopening the 13-mile stretch of track between Stirling, Alloa and the Longannet power station in Kincardine.

'Minimum disruption'

But the cost has more than doubled to �70m since the project was given the go-ahead.

A spokeswoman for the project said the delay in opening was the result of upgrade work to a level crossing, which was being carried out in the interest of public safety.

However, she did not reveal how much this would increase the cost.

She added: "The move from a half barrier to a full barrier level crossing with CCTV will have an impact on the completion date and on cost.

"The project team is working to keep these changes and any disruption to a minimum whilst safety continues to be of utmost importance."

The project will reopen about 21km of abandoned railway lines between Stirling and Longannet Power station.

It will also take freight off the Forth Road Bridge.