Subject to a mandatory standstill period, Amey has been awarded the contract worth around £500,000 for the project.
The contract involves design improvements for the A737 trunk road near the North Ayrshire town of Beith.
The design work is expected to get underway next month, which will allow a preferred option to be identified by the summer of 2014.
Transport Minister Keith Brown said: "The Scottish Government is working hard across the country to improve the trunk road network.
"Already in North Ayrshire, we are progressing the work for the A737 The Den scheme and we will shortly be publishing the draft Orders for the Dalry Bypass.
"This design work which will start next month will enable a preferred option to be identified by next summer.
"When the road improvements are completed they will help improve the road system around the town of Beith bringing improved traffic flow and road safety benefits benefitting road users and the local community alike."
The work will bring together the following three road schemes which were previously being progressed by North Ayrshire Council:
- Beith Bypass Carriageway Renewal
- Barrmill Road Roundabout
- Head Street/Wardrop Street Roundabout
(JP/CD)