A private monopoly will gain access to Victorians' personal information about properties and mortgages if the Andrews government proceeds with plans to privatise the land titles registry, industry groups say.

The sale of the NSW titles registry netted $2.6 billion but proved highly controversial, sparking a similar backlash last year from associations in the property sector.

The Victorian titles registry office, Land Use Victoria, is a government agency that keeps records of who owns land across the state and retains information about mortgages, titles, covenants, leases and easements.

The proposed sale has raised concerns about sensitive information falling into the hands of third parties.

The Law Institute of Victoria slammed plans to sell the registry as a "retrograde step".

"There are serious privacy and security issues around the protection of data and the government may be selling off a utility that earns a comfortable profit each year for a short-term financial gain," a spokeswoman said.

The institute argues that the registry is already efficient but there would be little incentive for a private owner to provide a better service as it would have no competitors.

"There are concerns that a buyer will try to increase profit from their purchase by hiking up user fees and cutting staff who have a great deal of experience and technical expertise."

But Treasurer Tim Pallas defended the move, saying the government had insisted it was committed to continuously reviewing Victoria's balance sheet.

He said the government wanted to identify opportunities to "recycle assets" and reinvest that money to build infrastructure.

"The Andrews Labor government will ensure all employees and their entitlements are protected throughout this process," he said.

The Sunday Age understands the government is examining options that would give it continued control of the data and maintain privacy.

The Community and Public Sector Union said Victoria's land titles office generated $300 million in revenue last year.

But it has raised concerns about job security and personal data going overseas, including the prospect of offshore call centres.

The union's Victorian secretary Karen Batt said the proposed sell-off was a "grab for a one-off sugar hit".

"It's nonsensical to remove a valuable annual source of public revenue," she said. "When fees are increased under a private provider, developers will pass that cost onto home buyers, impacting on housing affordability for Victorians especially first home owners."

Australian Institute of Conveyancers Victorian division president Jill Ludwell said it remained unclear how a new operator would handle the registry's data and whether it could be handed to third parties. "There's certainly been no consultation about it," she said.

In Britain plans to sell off the Land Registry met a furious response and the government eventually abandoned the idea.

The Victorian government's 2016-17 budget reveals it would "examine options to commercialise" the land titles registry.

"A detailed scoping study will identify appropriate options whilst ensuring data integrity and access rights are protected," the budget papers said.

It added that "divesting" or long-term outsourcing of the registry function would allow for more investment in other areas.