Intellectual property (IP) filings worldwide kept growing strongly in 2011, with patent applications for the first time exceeding 2 million, in which China toped the list, said a report released by World Intellectual Property Organization (WIPO) Tuesday.

World Intellectual Property Indicators 2011 shows patent applications increased by 7.8 percent in 2011, following a drop in 2009 and a strong rebound in 2010 of 7.5 percent. Utility models (UMs), industrial design and trademark filings grew 35 percent, 16 percent and 13.3 percent respectively.

Francis Gurry, WIPO Director General, pointed out sustained growth indicates that companies continue to innovate despite weak economic conditions.

China's State Intellectual property office (SIPO) overtook the United States to become the largest in terms of the number of patent applications, with 526,412 compared to 503,582 and 342,610 for U.S. and Japan.

Before 2011, China already accounted for most filings of UMs, trademark and industrial designs.

The report said the UM applications at SIPO accounted for most of the 670,700 global increase, and its rapid growth in trademark and industrial design filings have been the major contributor to growth in recent years.

The list of top 20 offices saw growth in industrial design applications includes 8 located in middle-income countries.

"Even though caution is required in directly comparing IP filing figures across countries, these trends nevertheless reflect how the geography of innovation has shifted,"said Gurry.