TORONTO -- Ontario colleges have been ordered to come up with new salary proposals for their presidents and other executives, after some institutions proposed pay hikes of 50 per cent.

The memo from the Liberal government comes at the same time a report says Ontario's 24 public colleges face a cumulative debt of $1.9 billion over 10 years in an age of declining enrolment.

A public-sector wage freeze is expiring, and colleges are posting their executive compensation proposals under new rules that came into force in September.

The new legislation-- introduced after years of complaints over generous salaries and severance packages for executives in the public sector -- created new compensation frameworks that cap salary and performance-related payments, prohibits signing bonuses, retention bonuses and cash housing allowances.

But Advanced Education Minister Deb Matthews said Thursday that the proposals are "concerning," particularly those that don't compare salaries to other colleges or organizations of a similar size.

"I'm saying to the colleges: 'What you've presented so far doesn't meet the test,"' Matthews said. "I'm not going to do your job for you. Go back, you know your sector best, you know your communities best, come back with a framework that actually does meet the letter of and the spirit of the legislation."

Some colleges have been using universities and hospitals as comparators.

The colleges are the first out with proposals under the new framework, so Matthews said hospitals and universities will be watching developments with interest.

In fairness to the colleges, Matthews said, the amounts posted were the maximums of a salary range, so she is asking them to be more transparent as to what compensation would actually be. Public-sector salaries are a thorny issue, she acknowledged.

"The numbers look too high and I get that," she said. "So that's why we've said, 'You have to justify it. You have to explain to people why you're paying what you're paying."'

Documents posted by Mohawk College in Hamilton show it proposed to raise the president's salary from $260,208 to up to $401,000. Algonquin College in Ottawa proposed to boost the president's salary from $321,165 to up to $445,000.

Meanwhile, PricewaterhouseCoopers concluded in a report that without further measures to increase revenues or cut expenses, Ontario colleges would have an operating deficit of $420 million by 2024-25 and a cumulative debt of $1.9 billion. Deferred maintenance costs are projected to be at $3.5 billion in that same year, the report said.

Deficits would be larger at smaller and more rural colleges, where overall enrolment declines across the province will be more acutely felt, the report said.

A request for comment to Colleges Ontario was not immediately returned.