New ferries capable of carrying 1,000 passenger and more than 100 cars are being sought for the Clyde and Hebridean routes.
The procurement process to build and design two new ships was launched by Transport Minister Keith Brown yesterday.
A pre-qualification questionnaire for the vessels was issued by Caledonian Maritime Assets Ltd (CMAL) in order to gauge market interest before issuing a formal invitation to tender.
The successful bidder will undertake detailed design and construction work of two 100m (328ft) ferries – each capable of carrying 1,000 passengers, 127 cars or 16 HGVs – as well as testing, equipping, launch and delivery.
The first vessel is to be delivered by the end of 2017 and the second some months later.
Mr Brown said: “The ferries are being designed to provide a fully flexible year-round service for Arran and the Uig triangle, subject to final review by CalMac Ferries Ltd, CMAL and Transport Scotland. The vessels they replace will be cascaded throughout the network.
“We are now focused on carrying out a competitive and detailed procurement process and look forward to adding the new vessels to the CalMac fleet.”