Specialist bidding teams are being stretched to the limit at major contractors pitching for the packages.
Crossrail chiefs are now believed to have delayed the award of three major stations until next year to ease pressure on competing firms.
Station work at Bond Street, Liverpool Street and Tottenham Court Road will now be awarded in 2012 rather than by the end of this year as originally planned.
The extension will not delay the construction schedule with all stations set to open on time.
Contractors bidding for tunneling contracts last year were understood to be unhappy about the tight tendering timetable and have asked Crossrail to ease the pressure with the station awards.
Contractors are currently waiting to see who has won the £250m Paddington Station job with an award due within the next two weeks.
- Balfour/Morgan Sindall/Vinci (Paddington, Farringdon,Whitechapel, Liverpool Street)
- BAM Nuttall / Ferrovial / Kier (Paddington, Farringdon, Bond Street, Tottenham Court Road, Whitechapel)
- Carillion (Paddington)
- Costain / Skanska (Paddington, Farringdon, Bond Street, Liverpool Street, Whitechapel)
- Dragados / Sisk (Tottenham Court Road, Whitechapel, Liverpool Street)
- Laing O’Rourke Construction (Paddington, Farringdon, Bond Street, Liverpool Street, Tottenham Court Road)
- Lend Lease Construction (Bond Street, Tottenham Court Road)