England is said to be dominating the higher education landscape
Universities in Scotland, Wales and Northern Ireland are losing ground to those in England, a report says.
The report, published by the vice-chancellors' group Universities UK, said that since devolution English universities had grown more quickly.
With different funding systems, they had more money and more students than their counterparts elsewhere, it said.
English universities had benefited most from research funding and the inflow of overseas students, it also concluded.
The report warns that these trends will accelerate if the government allows higher variable fees after it reviews the system next year.
It says: "It is too early to say why changes in cross-border flows of students are occurring and whether contrasting policies on fees are a factor - they clearly complicate students' decisions about where to study.
"Attempts to widen participation have not shown significant increases. The overall increase in international students has particularly favoured England, especially the south-east."
And it adds: "The longstanding complexities of research funding deepen with devolution. It is clear however that England's share of research money is increasing at the expense of the other territories."
The report calls on ministers from each of the four nations to communicate better with each other, and says there should be a more equitable formula for funding universities across the UK.
The president of Universities UK, Prof Rick Trainor, said: "Devolution has had an impact on public policy in almost every sector, and higher education is no exception.
"Although there have not been extreme variations in higher education policy across the devolved administrations, devolution has still led to a range of anomalies, discrepancies and complexities for the sector.
"For students, such complexities have made decisions about where to study much harder than formerly."