The Borders rail link will not reopen to trains until 2014
The completion target for the £295m rail link between Edinburgh and the Borders has been put back a year.
Finance Secretary John Swinney said on Monday that the process of appointing a contractor for the project would be under way by the end of the year.
However, the contract will not be awarded until autumn 2011, meaning works will not be completed until 2014.
It had previously been hoped that the route between Edinburgh and Tweedbank could be reopened to trains by 2013.
A spokeswoman for Transport Scotland said: "We expect to award the contract in autumn 2011 and anticipate construction to take around two and a half years.
"A key part of the competitive dialogue process will focus on contractors' ability to improve on this completion date.
"This will be an important part of the tender evaluation process."
The procurement process had originally been scheduled to get under way before the end of last year, but Transport Scotland said that "unprecedented changes" in the economic climate had delayed this.
The spokeswoman added: "A revised programme to accommodate this has been created."
Mr Swinney told a South of Scotland Forum meeting on Monday that the Scottish government remained committed to the scheme.
He said it could be a "significant catalyst" for economic growth and progress had already been made on the plans.