In class, National University of Singapore (NUS) computing undergraduate Teo De Zhao listens to the perspectives of fellow students and professors from around the globe.

In his second year, he was selected to do a one-year internship at the world's top technology hub - Silicon Valley.

There, the 26-year-old attended talks by founders of successful start-ups and helped forge partnerships with technology giants such as Google and Amazon.

Mr Teo's university experience sums up NUS' global approach towards education and research.

The university was yesterday named the world's fourth most international university, edging out the likes of Oxford, Cambridge and Harvard. It was rated fourth out of 150 universities in the Times Higher Education ranking.

The top two spots were held by Swiss universities ETH Zurich and Ecole Polytechnique Federale de Lausanne. The University of Hong Kong came in third.

The ranking takes into account a university's proportions of international students, international staff and journal publications with at least one international co-author.

NUS was ninth in last year's league of international universities.

This year's ranking was done with a revised methodology.

It included for the first time a university's global reputation, which makes up 25 per cent of the total score.

This measures the ratio of international votes to domestic votes through an invitation-only survey, which asks leading scholars to name the world's best universities for teaching and research in their field.

NUS president Tan Chorh Chuan said about eight in 10 of its undergraduates get to study abroad, including semester-long student exchanges at 300 universities in more than 40 countries.

It also collaborates with overseas universities to offer more than 70 joint-, double- and concurrent degree programmes.

"In short, to enhance learning outcomes, we take our students to the world, and we bring a world of learning to our students in Singapore," he added.

Prof Tan said NUS welcomes high-quality faculty and students from around the world.

It has staff and students from about 100 countries, who bring with them valuable academic expertise as well as different social and cultural perspectives.

Times Higher Education World University Rankings editor Phil Baty said: "NUS, and indeed Singapore more widely, has become a powerful magnet for international talent - drawing in leading thinkers and scholars from right across the world, and forming the base for exciting and dynamic global partnerships.

"NUS stands as the flagship of a true global knowledge hub."

He added that the "best universities in the world live or die by their ability to attract the brightest talent from all across the world" and a university cannot be world-class without a global outlook, network and pool of talent.

Mr Baty warned that changing attitudes and policies towards immigration across the world have the potential to "profoundly change the flow of global talent and shift the world balance of power".

He singled out the United States and Britain, which are looking at tightening immigration laws.

"Restrictions to the mobility of academic talent in these countries will inevitably harm their position while other countries welcome talented immigrants with open arms, and their universities strengthen," he said.