The London School of Economics has the highest proportion of "world-leading" research among UK universities.
In rankings based on research grades, University College London has overtaken Cambridge for the first time.
The research ratings will determine the allocation of £2bn public funding for universities each year.
The findings are based on a massive funding-council project evaluating the quality of research at universities across the UK, with the last similar exercise having been published in 2008.
The Research Excellence Framework measured the quality of research from more than 52,000 academics in 154 universities.
It revealed the rise of London institutions, catching up and overtaking Oxford and Cambridge and the decline of big universities in the north of England.
'Taking a hammering'
William Cullerne Bown, of Research Fortnight, which analyses research and funding, said "London looks unstoppable" and universities in the capital "could now eclipse Oxbridge".
He said this process would be further accelerated by major plans for expansion at University College London (UCL) and Imperial College.
"The biggest losers are Manchester, Liverpool, Sheffield, Birmingham and Leeds. The North is taking a hammering," he added. Read the whole article.
This article was written by Sean Coughlan and was originally published by BBC News.