Profit-making firms that sell products and services to schools or sponsor academies should be given an "ethical audit" first, according to a report.
The study, by academics at the Institute of Education in London, said state education around the world was increasingly exploited by business, and some were "highly inappropriate for education-related work".
They pointed to reports last year that Outwood Grange College in Wakefield had been considering - but later decided against - a partnership with BearingPoint, a multinational company that has advised President George Bush on the reconstruction of Iraq.
Stephen Ball, one of the academics, said: "I have an ethical ISA where they vet the companies my money is invested in to make sure there is no connection to the arms trade or exploitative business.
"I imagine a similar model for education contractors - there needs to be an official process."
The report was commissioned by Education International, which represents teachers' unions in 170 countries, including Britain.
The academics said they had charted "privatisation by stealth" in education in the developed and developing world.
There was now a whole generation of "edupreneurs" whose only aim was to make money and influence the curriculum and policy to their advantage, they said.
The report added that market-based models of education - including Britain's focus on choice and diversity in schools, league tables and performance management - were creating "ethical dilemmas" for teachers, who are torn between the interests of school and students.
It also criticises the World Bank's influence in promoting the private sector for education in the developing world.
"Forty per cent of loans to these countries require a degree of private sector involvement," said Deborah Youdell, who co-wrote the study.
Bob Harris, senior consultant to Education International, described the creeping privatisation as "not so much deregulation but re-regulation and a new form of control".
"Markets are seen as connected to the cycle of boom and bust. Is it something we want education dragged along towards?" he said.
"To do so would be to mortgage the future of children - and that mortgaging would involve a lot of sub-prime."
Hidden Privatisation in Public Education is at: www.ei-ie.orggatsendocumentation.php.