The University of Tokyo remains the most prestigious institution of higher education in Asia, according to a study released Tuesday, but the editor of the study said Japan is slipping in relative academic prominence and some action is needed to fight competition.

The institution came in ninth in this year's Times Higher Education World Reputation Rankings, an annual survey of academic opinion, beaten only by American and British universities.

This year's global index of university brands saw Harvard University once again come on top, with the University of Tokyo, also known as Todai, slipping one place from 2012.