Australian National University astronomer Professor Brian Schmidt was expected to enjoy a $1 million-plus salary when he takes over from Professor Ian Young as vice-chancellor next January.

But executive remuneration consultant John Egan said the joint recipient of the 2011 Nobel Prize for Physics may have to prove himself in the top job before extra financial rewards were handed over.

"I would anticipate the [incoming] V-C would not be paid less, given his scholarship, but would not be paid significantly more," he said.

Professor Young's salary package was in the range of $970,000 to $984,999 last year. Entitlements also include a rent-free residence and a car.

The outgoing leader was paid $200,000 less than long-serving vice-chancellor Ian Chubb when he began the role in 2011, leaving his position of seven years as vice-chancellor of Swinburne University of Technology.

Professor Chubb was paid more than a million dollars a year.

Mr Egan, chairman of Egan Associates and an adjunct professor with the University of Sydney's business school, said there would also be an attraction for the university to allow the scholar to continue his leading-edge research by providing him senior research staff.

"Professor Schmidt would bring to the university the highest level of academic excellence, and he may seek to remain in a research role partly," he said.

"The university may be prepared to pay a premium for that presence and the internationally acknowledged research expertise – they're unlikely to pay a premium for his administrative expertise."

While it is not known publicly what Professor Schmidt is paid this year, ANU's latest annual report suggested a major pay rise would occur, with the two highest paid "senior executives" after the vice-chancellor receiving between $565,000 and $579,999 last year.

The University of Sydney vice-chancellor Michael Spence is reportedly the highest paid in the nation, earning a salary package of $1.3 million last year.

An ANU spokesman said Professor Schmidt's 2016 salary would remain in confidence until released in the annual report next year. Professor Schmidt said in June he would keep in touch with astronomy after his promotion, but a continuing research role would appear unlikely given competing commitments.

The America-born, Harvard Phd has worked at the ANU since 1995, but not in the university management. He is a member or chair of a wide range of corporate or advisory boards, from Questacon to the Australian Wine Research Institute.

University of Canberra vice-chancellor Stephen Parker was paid between $900,000 and $909,999 last year, including superannuation.

There was no comment from Professor Schmidt this week.