London: UK universities have taken four of the six top slots in a global university "league table" for 2011-12.
With US`s Massachusetts Institute of Technology leading the list, UK`s Cambridge, which was top last year, stood second and Harvard University ranked third in the QS World University Rankings, based on a number of criteria.
University College, London (UCL), Oxford and Imperial took fourth, fifth and sixth places respectively.
Seventh place was awarded to Yale University, followed by University of Chicago, Princeton University and the tenth position to California Institute of Technology.
Ben Sowter, of QS Research, warned higher fees and new visa rules could see UK universities struggle next year.
Students trying to get ahead of a trebling in fees for English undergraduates had produced a surge in applications to start university in autumn 2011, Sowter told BBC News.
"We won`t know for sure until the 2012 results come in, but we may see a drop off next year," he said.
He also said tougher visa rules for international students could deter some from applying to UK universities.
Just 40 per cent of UK employers agreed visa regulations had helped them hire international graduates - globally the figure was 70 per cent said Sowter.
The UK Government has been widely criticised by MPs within the past week for tightening the student-visa system.
Both argued overseas students should be reclassified so that they would not count towards migration limits, to allow the UK to continue to expand its share of the overseas student market.
The QS rankings rate the world`s top 400 universities, evaluating each institution`s strengths in research, teaching, the employability of its graduates and international outlook.
"If we are serious about staying on top, the government must concentrate investment where it will have the most impact - in our world-class research-intensive universities," director general of the Russell Group of research-based universities Dr Wendy Piatt said.
"The government has put our university system on a stable footing by introducing substantial government-backed loans, which secure a sufficient stream of funding for the sector while ensuring there are no upfront fees and a progressive repayment system for students," spokesperson of Department for Business Industry and Skills said.
"We believe the attractiveness and quality of our higher education will be sustained by our reforms," the spokesperson added.