Mary Creagh, on a visit to Glasgow, said the proposal of a "new deal" to allow public companies to compete alongside private ones for rail franchises, such as the West and East Coast main lines, would apply in Scotland with Holyrood getting powers to create the new system, covering ScotRail.
The Scottish Government has said it will consider different ownership models for the rail network under independence amid complaints that UK law prohibits domestic public sector companies from running Scottish trains but does not exclude foreign public companies.
Yet Labour stressed Scotland "does not need independence" to reform rail ownership as it would devolve the power to consider public sector bids if it gets into government.
Ms Creagh, who will be joined in outlining Labour's new approach by James Kelly, Scottish Labour's Transport spokesman, said: "The first priority should be passengers, not profit. That's why we need a new deal for our railways, in Scotland and across the UK."
She noted how the Scotland to London East Coast line, which had served Scottish passengers well, had worked in public hands.
"That's why Labour will learn the lessons from East Coast and make sure that public sector companies can compete on a level playing field with the private sector," she explained.
Mr Kelly added: "We will devolve these powers to the Scottish Parliament and open up our railways to public sector companies.
"We need our railways to be working for passengers. Under the SNP more than half a billion pounds of public money funds the rail franchise. That's why we need public sector companies to be able to compete on a level playing field with the private sector," he added.
But an SNP spokesman said: "Only a Yes vote will allow governments elected by the people of Scotland the powers needed to decide the best way to structure our railways."