Universities in Birmingham, Coventry, Warwick and Wolverhampton have been accused of secrecy after refusing to answer questions on spending on flights, hotels and expense claims.
The group was among 24 universities out of 155 who failed to respond to a Freedom of Information request from the University and College Union (UCU).
A report, based on data from the FoI request, showed university bosses were spending as much as £60,000 a year on air fares and enjoying first class and business class flights.
At Aston University, Professor Julia King spent £18,625 on flights, of which 95 per cent were in business or first class.
The report found The University of Warwick employed 158 members of staff on an annual salary above £100,000 in 2013/14. The equivalent figure for the University of Birmingham was 128.
UCU official Anne O'Sullivan said: "This report lifts the lid on the inconsistent and arbitrary nature of senior pay and perks in our universities and shines a light on the murky world of shadowy remuneration committees who sign off these deals. We need a far more transparent system that allows for proper scrutiny of spending at the top."
A spokesman for Warwick said: "We regularly respond to a range of FOI requests on these matters; indeed we think we have been amongst the most open in our responses. The only thing we have declined to provide are minutes of our remuneration committee as we believe it would inhibit the committee's ability to debate."
A spokesman for Aston said: "Aston has a good relationship with the campus trade unions and we are transparent on issues of costs and pay – hence our provision of unredacted minutes of our remuneration committee."
A spokesman for the University of Birmingham said: "Details of the vice-chancellor's pay and benefits are published in our annual accounts. We have always been open about this. Indeed, in responding to UCU's FoI request we explained where we were unable to provide the information in full and offered to provide some of the information requested but this offer was not taken up."
Professor Alan Richardson, chairman of Coventry University's board of governors, said: "The university has always maintained transparency around its income and expenditure."
University of Wolverhampton secretary Emma Wedge said: "The university is open and transparent and much of the information requested is readily available on our website, including the vice-chancellor's salary.
"We only exempt information that relates to our students' and staff members' personal data or accounts that have not yet been published."