China has become the first country to file more than a million patent applications in a year, leading a global innovation surge that has defied sluggish economic growth, the UN said Wednesday.

"The figures for China are quite extraordinary," said Francis Gurry, head of the United Nations World Intellectual Property Organization (WIPO) while launching the body's annual report.

China registered 1.1 million patents in 2015, more than the top three runners-up combined, WIPO said, referring to the United States (578,000 applications), Japan (325,000) and South Korea (214,000).

Chief WIPO economist Carsten Fink linked the Asian giant's performance to "the laws of compound growth", where a massive nation with sustained economic expansion has seen a dramatic rise in innovation.

Globally, patent applications hit 2.9 million in 2015, a near-8 percent rise on 2014 figures, the report said.

By sector, computer technology led the way with 7.9 percent of total applications, followed by electrical machinery (7.3 percent) and digital communication (4.9 percent).

Gurry said there were dangers in trying to draw broad conclusions about the global economy based strictly on intellectual property trends, but noted that innovation has in recent years proven more robust that general economic growth.

"What is striking is that you have a performance in respect of intellectual property that is not similar to the general outlook for the global economy," the WIPO chief told reporters.