Construction News understands that Interserve and McLaughlin & Harvey are bidding for the scheme in Ashton, which will improve transport routes within the town.
Eric Wright Group was also originally on the tender list but told Construction News that it declined to bid for the project.
Plans for the project were approved in February this year, with prequalification documents sent out in May.
The new interchange will be built on the site of an existing bus station in Ashton and will link with existing Metrolink tram services.
Plans are currently at detailed design stage, following five separate public consultations.
Transport for Greater Manchester said the new interchange design will free up a “large area of land” that had previously been restricted.
Work on the interchange is due to start in 2017 and will be fully operational within 18 months.
Funding for the project is supported by TfGM and central government through Greater Manchester’s local growth deal programme.
It is the latest project in TfGM’s interchanges programme, with previous overhauls taking place at Bolton, Altrincham and Wythenshawe.
Kier was chosen as the main contractor for the £24.3m scheme at Bolton, due to be completed in December this year, while Laing O’Rourke was picked as main contractor for Altrincham’s £19m interchange, completed in December 2014.
The works do not fall within Greater Manchester’s new £200m civil engineering framework, which was released earlier this week.
McLaughlin & Harvey has been contacted for comment, while Interserve declined to comment.