Fast food chains McDonald's, Hungry Jacks, KFC and Starbucks and banking giant CBA will be forced out of their prime, high-trading Swanston Street stores to make way for the government's $10.9 billion Melbourne Metro Rail project.

The business behemoths will join a growing exodus of key retailers abandoning the city's main shopping core, Swanston Street, ahead of years of disruption expected from work on the project's centrepiece tunnel and two city stations.

Metro authorities are negotiating the compulsory acquisition of four Swanston Street properties between Young & Jackson's Hotel on Flinders Street and the Nicholas Building on the corner of Flinders Lane.

All four buildings – along with the Port Phillip Arcade behind – will be razed to make way for the rail project's CBD South station.