Beijing boasts the world's second-largest number of most valuable tech startups, showcasing its advance in the sector.

The number of so-called unicorn companies — tech startups valued at more than $1 billion each — has reached 40, second to Silicon Valley in the United States.

This is according to the Zhongguancun Unicorn List released on Monday by the Great Wall Enterprise Institute, a research house in the capital.

They account for half such companies in China, with an aggregate valuation of $146.2 billion, including three worth more than $10 billion each.

Smartphone maker Xiaomi, valued at $46 billion, ranks first, followed by group-buying player Meituan-Dianping, valued at $18 billion.

Didi Kuaidi, China's largest ride-hailing app, valued at $16.5 billion, came in third, the report said.

Lin Renxiang, an analyst at iResearch Consulting Group, said, "Beijing is China's Internet center and many Internet companies are based in the city.

"Moreover, Beijing is home to China's top universities and research institutes, which cultivate technical talent for these unicorn companies."

Lin estimates that more unicorn firms are likely to appear in service fields including big data, cloud computing and mobile health.

According to the list, most unicorn companies operate in e-commerce, Internet finance, consumer electronics, transportation and big data.

These companies have seen dramatic growth, with more than 30 unicorns formed after 2010 undergoing vigorous initial development.

Liu Hang, spokesman for the management committee at the Zhongguancun Science Park, estimates that with technical breakthroughs in big data application, intelligent hardware, artificial intelligence and virtual reality, a series of new unicorn companies will emerge in these fields.

By December, there were 70 unicorn firms nationwide. Beijing ranked first with 40, followed by Shanghai (15), Hangzhou (4) and Shenzhen (3), the report said.

Last month, a list issued by Fortune magazine showed the number of unicorn companies globally had increased to 173, with 35 in China.