Bidders for the £90 million Western Range and Concourse at King’s Cross have been whittled down to four firms.
Carillion has pulled out, leaving a list of Balfour Beatty, Kier, Taylor Woodrow and a Laing O’Rourke/Costain joint venture still in the hunt.
A source from a bidder said: “The tender return date has been put back. We’ve now got until the end of February to get our final bids in - an extra month.
“I suspect someone asked for an extension, probably because of the timing. It’s a complex job and with Christmas, there just wasn’t enough time to get everything done by the end of January.”
Network Rail remains positive about delivering the project. A spokeswoman said: “We have contingency plans in place for delays like this. Bidders should have no concern that this will impact on the delivery date.”
Work, expected to start later this year, includes building a 8,000 sq m, two-storey, semi-circular concourse between the main train shed and the rear of the adjacent Great Northern Hotel, as well as refurbishing the existing westerly range buildings running parallel to the most western platform. These will be used as offices for train operators and other staff.
Interests have also been expressed for package five - the shared service yard and link room.
Kier, Carillion, Morgan Est and Taylor Woodrow are all understood to be bidding for this work, worth £30 million.
The job involves constructing a subsurface link providing logistical access for station operations such as onboard services, waste removal, catering and retail deliveries and location of utility equipment.
Both contracts are part of a £400 million programme to transform King’s Cross station by 2013. Later this year tenders will be invited for the £18 million revamp of the main train shed roof as well as a £22 million job to modernise platforms.