China National Offshore Oil Corp signed a strategic cooperation framework agreement with Brazilian oil and gas company Petrobras on Monday in Beijing, eyeing to further deepen cooperation in oil and gas exploration and development, as well as in the refining and chemical industry, it said.

The two sides will also further step up cooperation in engineering construction as well as oilfield services and crude oil trade, said the company.

CNOOC said the signing is an important milestone in the development of oil and gas cooperation between CNOOC and Petrobras and is of great significance to promoting the construction of the Belt and Road Initiative and international energy cooperation.

CNOOC has been actively participating in the Brazilian oil and gas markets in recent years. It currently has a 7.34 percent interest in the integrated development of the Buzios field in Brazil, the world's largest deepwater pre-salt-producing oilfield with an average water depth of about 2,200 meters.

CNOOC currently owns five deepwater oil and gas block assets in Brazil. In 2013, CNOOC, Petrobras, Shell, TotalEnergies and China National Petroleum Corp formed a consortium to win the Libra block, entering the Brazilian subsalt ultra-deepwater oil and gas field for the first time.