BEIJING, Jan. 15 (Xinhua) -- The world's top 500 firms increased investment in China last year, showing continued confidence in the economic outlook of the world's second largest economy, according to China's Ministry of Commerce.

　　Multinational corporations including Germany's Audi, Italy's Fiat, Samsung from the Republic of Korea and Intel from the U.S., all increased their investment in China in 2015, each channelling more than 100 million U.S. dollars, data from the ministry showed.

　　The number of regional headquarters and research institutes set up by these corporations also continued to rise last year. So far, more than 2,400 research institutes have been established in China by international companies, according to the MOC.

　　In the January- November period last year, the number of newly registered foreign-invested enterprises hit 6,040 in Guangdong, Tianjin and Fujian free trade zones, attracting 445.8 billion yuan (50.3 billion U.S. dollars) of contracted foreign investment.

　　The introduction of the negative list system, which defines sectors and businesses that are off limits to foreign investment, and the slashing of red tape, helped motivate foreign investors, according to the MOC.

　　The latest MOC figures showed that foreign direct investment (FDI), which excludes investment in the financial sector, rose 6.4 percent year on year to 126.27 billion U.S. dollars in 2015.