The firm, which recently completed the on-time, on-budget £294m Borders Railway, will oversee delivery of the four-year railway upgrade project – the first phase of which is due for completion in 2019.
The job involves doubling track for 16 miles between Aberdeen and Inverurie, building a new station at Forres and extending platforms at Insch and Elgin to accommodate longer trains.
Signalling systems will be upgraded along the route and infrastructure installed to allow new stations to be built at Dalcross and Kintore.
Plans for these stations are being developed separately by HITRANS and NESTRANS respectively, while a further phase of the Aberdeen-Inverness Improvements Project is to be developed.
Engineers are currently carrying out ground investigation, site survey and vegetation clearance works on the line as part of the project and main construction works will begin in spring 2016.
Jerry Dickson, framework director for BAM, said: ‘Together with our partners AECOM, CH2M, Stobart Rail and Siemens, we are looking forward to commencing work on the Aberdeen to Inverness Enhancement Programme.
“This essential programme of works will improve connectivity between the major cities of Aberdeen and Inverness, with wider enhancements for the local communities in the north of Scotland.”