Harvard has retained its top place in a world universities ranking this year, but Cambridge and Oxford have moved up to second and third.
Cambridge came top in the opinions of the academics
They displaced the Massachusetts Institute of Technology, which is now ranked fourth in the Times Higher Education Supplement's table.
There are 29 British universities in the top 200 - six more than last year, a bigger rise than any other country.
Another is now in the top 10: Imperial College London, up from 13th last year.
Imperial this week agreed a formal split from the University of London in what was described as an "amicable divorce".
It expects to become independent in July 2007, to coincide with its centenary.
The university rankings are based on a survey of 3,703 academics worldwide.
They were asked to nominate up to 30 institutions they regarded as the best at research in their own fields.
On that measure, Cambridge came top, followed by Oxford then Harvard.
Hundreds of graduate employers were also surveyed.
Other factors influencing the rankings included the ratio of academics to students and success in attracting foreign students and internationally renowned academics.
The editor of the THES, John O'Leary, said: "The presence of so many American and British universities at the top of the ranking owes something to the dominance of English as a world language in academic life as well as in business, but by every measure these are outstanding institutions."
4: Massachusetts Institute of Technology
7: California Institute of Technology
8: University of California, Berkeley
9: Imperial College London