Patent applications by enterprises owned by the central government have risen by nearly 30 percent annually in recent years, said the State-owned Assets Supervision and Administration Commission (SASAC) on Friday.

The 169 enterprises under the supervision of the SASAC filed approximately 6,580 patent applications, with 2,853 of them being in invention, SASAC said.

It also said that 3,886 patents have been authorized, 1,265 of them for inventions.

The majority of the patent applications involve the petroleum, petrochemicals, metallurgical and military industries and scientific research institutes. Applications by the oil and petrochemical industries made up nearly 30 percent of the total.

China National Petrochemical Corporation (Sinopec) and China National Petroleum Corporation (CNPC) top the list in terms of both patent applications and authorized patents.

In 2004, these enterprises invested 76.79 billion yuan (9.47 billion US dollars) in technological innovation, accounting for 1.5 percent of their total sales income.

Source: Xinhua