Mr O'Leary said teaching in English also gave UK universities a big advantage, particularly in attracting international students.

BBC: 'Research key' to universities leading global rankings

Speaking after the summit, Edinburgh University principal Prof Sir Timothy O'Shea claimed a "serious commitment" of public funds was needed for higher quality universities in Scotland in the future.

BBC: Summit held on Scottish higher education funding

John O'Leary, of the QS Global Academic Advisory Board, said the number of UK universities in the top 20 for at least one subject was "far in excess of the total achieved by any other country apart from the United States".

BBC: Oxbridge rated best in world for seven key subjects