China's outbound investment is expanding almost three times as fast as the nation's GDP, and the emphasis is shifting away from resources and toward the service sector and industry, a private equity firm said in a report on Wednesday.

A Capital, which has offices in Beijing, Brussels and Hong Kong, said that from January to September, China's ODI totaled $73 billion, up 20 percent year-on-year. The GDP growth rate for the period was 7.7 percent, the report added.

The firm said China's ODI will likely equal inward foreign direct investment in the next three years, with an additional $500 billion in new outbound investment by 2016.