The chairman of England's new higher education regulator has vowed to address the "out of kilter" pay of some university vice-chancellors.
Sir Michael Barber told the BBC the Office for Students would be publishing comparisons with other staff and pressure those setting wages.
But he said the authority did not have powers to set a pay cap.
Bath University's vice-chancellor has faced protests by students and staff over her £468,000 pay deal.
When it begins work in 2018 the Office for Students will be able to examine whether universities offer value for money and require institutions to explain any pay packet over £150,000.
Speaking on BBC Radio 4's Today programme, Sir Michael said: "We will take this very seriously but we aren't going to interfere directly with university autonomy which is fundamental to the success of British universities."
He said: "What we are not in a position to do is simply to tell universities what to pay their vice-chancellors.
"But there are things we can do. We can publish ratios of the vice chancellor's pay to other people's pay, to the average pay or to the lowest pay, and those ratios will vary enormously by institution and that will be one indicator that things are out of kilter."
Motion of no confidence
Sir Michael added there are "some vice-chancellor's pay packets that look out of kilter with the performance of their institutions and their contribution".
An annual survey of vice-chancellor pay by accountants Grant Thornton found salaries between 2009 and 2016 rose by 13% - about the same as average UK earnings.
However, there were examples of institutions in which the pay of the vice-chancellor has increased significantly since 2009.
Among the 156 higher education institutions it surveyed, the average salary for a vice-chancellor in 2015-16 was £246,000. Pension contributions, benefits and bonuses take that to £281,000.
Bath University's Dame Glynis Breakwell's total pay and benefits makes her the highest paid university leader in the UK.
She has already announced a review of the university's remuneration committee, which decides her pay, and on Thursday narrowly won over a motion of no-confidence after 350 staff called for her resignation.