China Petrochemical Corp.'s $3.54 billion acquisition of a stake in Galp Energia SGPS SA (GALP)'s Brazilian unit was approved by the Chinese government in March, according to a statement on the website of the country's National Development and Reform Commission.

Asia's biggest oil refiner, known as Sinopec Group, agreed in November to buy a 30 percent stake in the unit of Portugal's biggest oil company. The state-owned company, based in Beijing, also agreed to subscribe for new shares and assume shareholder loans, taking its total cash investment to $5.18 billion.

Galp has stakes in four offshore blocks in Brazil's Santos Basin, including a 10 percent share in Lula, the largest crude discovery in the Americas since Mexico's Cantarell field in 1976. Lula, formerly known as Tupi, holds an estimated 6.5 billion barrels of recoverable oil and equivalents.

Sinopec Group is the parent of Hong Kong and Shanghai- listed China Petroleum and Chemical Crop., known as Sinopec. The unit's shares traded 0.8 percent lower at HK$8.29 in Hong Kong as of 11:59 a.m. in Hong Kong. The benchmark Hang Seng index dropped 0.2 percent.