Two Singapore universities have again emerged among the best in the world in a global university ranking, taking top-10 spots globally in 10 subjects.

The ranking was done by London-based education and career consultancy Quacquarelli Symonds (QS) - more well-known for its annual ranking of worldwide universities. The latest exercise focuses on a narrower spread of disciplines.

Together, the National University of Singapore (NUS) and Nanyang Technological University (NTU) also helped Singapore achieve more top-20 placements across 46 subjects than any other Asian nation.

Singapore's best showing was in civil and structural engineering, where NUS placed fifth in the world, though it was a drop of two places from last year.

The country's second best ranking was in electric and electronic engineering, where NTU improved two places to rank sixth.

Singapore's universities took 34 out of 122 top-20 positions achieved by Asian universities this year. This was more than twice as many as China, and more than Japan which achieved 32 top-20 rankings.

Noting a slight drop in the number of top-10 and top-20 placements achieved by NUS and NTU compared with last year's rankings - 15 to 10 and 36 to 34 respectively - QS said the downward movements were minor, with an average drop of three places.

"(This) can predominantly be explained by the typical fluctuations that occur at the top end of the global rankings," it said.

Singapore Management University, though a young institution, also featured on the list, placing in the top 100 for accounting and finance, and business and management studies.

QS introduced rankings by subjects in 2011 and its latest list released today is based on an assessment of 1,127 universities and colleges from 74 countries, on their academic reputation, employer reputation and research impact, and covers 46 subjects.

Professor Tan Eng Chye, deputy president (academic affairs) and provost of NUS said the university's performance in the latest rankings reaffirms its strong expertise in areas such as engineering and technology, natural sciences, social sciences and management.

"We will continue to deepen our efforts in delivering quality education and engaging in cutting-edge research, and strive towards creating distinct value for Singapore, the region and beyond," he said.

On the global front, University of Cambridge topped the subject rankings by placing top 10 in 36 subjects.

To view the full university ranking lists by subject, visit https://www.topuniversities.com/subject-rankings/2017