Politicians would be given power to set Greater Manchester's bus routes and fares under plans to bring the transport network under public control.
Mayor Andy Burnham wants to introduce a model similar to London, which would see bus operators bidding to run services on a franchise basis.
The proposals would help to make public transport less "fragmented and unreliable", Mr Burnham said.
Stagecoach said taxpayers would have to foot a "massive bill" for the plans.
The metropolitan mayor said an assessment into the region's bus services had been completed and he would ask Greater Manchester Combined Authority to approve the proposals on Friday.
The plans would be subject to a public consultation.
Greater Manchester would become the first city region outside London to make use of new powers under the Bus Services Act 2017 to take control of regulating its buses.
Campaigners say that, since deregulation of the network in 1986, bus operators have "cherry-picked" the most profitable routes and leave some communities underserved.
They say franchising would allow authorities to use profits from busy routes to subsidise less busy but vital routes.
Mr Burnham was speaking at the launch of his ten-year plan to reshape Greater Manchester's public transport.
He promised passengers would be able to move between buses, trains and trams with capped fares and a single Oyster-style ticketing system modelled on London.
"Our current public transport system is fragmented and unreliable, with often confusing ticketing and passenger information," he said.
"A truly integrated transport network has the potential to transform Greater Manchester.
"An important part of this is reforming our bus market."
Pascale Robinson, who runs the Better Buses for Greater Manchester campaign, said: "Public control of our buses would mean affordable fares, a smart card with a cap, and services that are accountable to our communities, like they are in London."
Bus operators favour reform via a "partnership" model which would mean they worked closer together to provide a comprehensive network.
A Stagecoach spokesman said the mayor had provided "no evidence to support his claim that franchising is better than a partnership approach".
He added: "He is keeping Greater Manchester's taxpayers in the dark about the massive bill they would have to pay for a London-style bus system."
Gary Nolan, chief executive of One Bus, which represents the majority of the region's bus operators, said: "We urge the mayor to put passengers before politics and let the public know how long this process will take and what tax increases they will face to achieve his vision."