Nine UK universities in new global reputation rankings
The UK is home to nearly a 10th of the most prestigious universities in the world, but there are warnings that their status among the global elite "is not guaranteed".
New international rankings, based on reputation, include nine UK institutions this year, down from 10 that made the top 100 last year.
Oxbridge continues to dominate, with Cambridge the top ranked UK university in this year's Times Higher Education World Reputation Rankings, taking fourth place, with Oxford one spot behind in fifth.
Two other UK institutions - both in London - University College London (joint 18th) and Imperial College London (20th), made it into the top 20.
But Phil Baty, THE's editorial director of global rankings, warned that while the nation has some of the most prestigious universities in the world, these institutions have either "fallen down the global pecking order, or stayed static".
The rankings look at each institution's reputation for research and teaching, based on a survey of more than 10,100 academics in 138 countries.
Other UK universities to make it into the top 100 this year were the London School of Economics and Political Science (25th), Edinburgh University (35th), King's College London (42nd), Manchester University (51-60) and Warwick University (81-90).
Mr Baty said: "The UK has some of the most prestigious universities in the world, admired across the continents."
"But their status is in no way guaranteed - all UK universities have either fallen down the global pecking order this year or stayed static."
"This should give pause for serious thought as the country seeks to champion its status as 'global Britain' in a post-Brexit world."
Overall, Europe claimed 33 places, with the UK the best represented, followed by Germany (six universities in the top 100) and The Netherlands (five universities).
The UK was one of only two countries with institutions in the top 10, the other was the United States, which took the other eight places.
The US had 44 universities in the top 100 overall.
Taking top spot again this year was Harvard, followed by the Massachusetts Institute of Technology in second place and Stanford University in third.
Alistair Jarvis, chief executive of Universities UK, said: "It is clear from this, and other such rankings, that the UK has one of the strongest university sectors in the world. This success in in large part due to the quality and dedication of staff working in our universities."
"However, we must not be complacent. Many of our major competitors are growing their investment in higher education and doing more to attract international talent."
"In order to maintain our global position, we need to continue to invest in higher education and ensure that the UK projects a more open and welcoming message for talented international staff and students."
A spokeswoman for the Russell Group said: "Russell Group universities are recognised around the world for their excellence."
"The flow of people and ideas is crucial to our ongoing success. We need a dynamic environment for research and teaching in the UK and that will depend on our ability to recruit and retain global talent post-Brexit."
"We also need to ensure we can strengthen international collaborations to remain at the cutting edge of research and innovation."