Balfour Beatty, Skanska and High Wood Health (Laing O'Rourke) have made it through to the final stages of selection.
Client NHS Dumfries & Galloway is aiming to have construction start on site in spring 2015, with the new hospital being open to patients in the first half of 2018.
Chief executive Jeff Ace said: “The calibre of companies that have engaged with us at the bidding stage demonstrates the scale of this development. I've been extremely impressed with the quality of submissions and our project team will now face an extremely difficult task in selecting our eventual partner in the delivery of Scotland's latest and best acute hospital."
Mott MacDonald and Keppie Design have been working as technical consultants on the project since July 2012.