The job has attracted two Spanish contractors in joint venture with UK contractors.
The bidders understood to have made the cut for the £140m scheme are:
- Bam Nuttall/Spanish firm Ferrovial
- Dawnus/Spanish firm Obrascon Huarte Lain
- Morgan Sindall/Griffiths
The successful bidder will develop the preliminary design that was presented to public inquiry in 1998.
This involves upgrading to dual 2-lane standard the existing 3-lane A465 Trunk Road between its junction with the A4077 at Glanbaiden Rroundabout, Gilwern and its junction at Brnmawr in Monmouthshire.
This links section 3 works between Brynmawr and Tredegar, which Carillion is building.
The contractor will work with the roads team at the Welsh Assembly and its agent E C Harris to carry the project through development, statutory procedures and construction.