China National Petroleum Corp., the country’s biggest oil and gas producer, will seek outside investors for its oil and gas exploration and refining businesses as the nation opens up state companies.

Six sectors including oil and gas reserves, unconventional oil and gas exploration, pipelines, refining, overseas businesses and financial units have been chosen for possible equity partnerships with private investors, the China Securities Journal reported Wednesday, citing Zhou Jiping, chairman of the state-owned company.

The board hasn’t decided on the shareholding structure of such partnerships, Zhou said.

The move is the latest sign that China’s energy companies are seeking to add outside investors. China Petroleum & Chemical Corp., known as Sinopec, said last month it would seek private investors for as much as 30% of its oil retail unit, which includes more than 30,000 fuel stations.

Chinese premier Li Keqiang said in a speech to the National People’s Congress that non-state capital will be allowed to invest in areas such as banking, oil and resources development, the official Xinhua News Agency reported.

CNPC is open to all forms of partnerships as long as they are good for risk and profit-sharing and accelerate development of the oil and gas industry, Zhou said, according to the Securities Journal.

Investment in individual projects will be judged on a case-by-case basis, though the general principle is to break monopolies and promote competition in those sectors, Zhou said. Beijing-based CNPC is the parent of listed unit PetroChina.

Li Runsheng, CNPC’s Beijing-based spokesman, did not answer two calls to his office seeking confirmation of Zhou’s comments.