China National Petroleum Corporation plans to invest at least $2bn in Peru over a decade, according to a top CNPC executive, following its purchase of Petrobras's assets in the South American state.

CNPC, China's biggest oil and gas firm and parent of PetroChina, has obtained environmental permissions to carry out $1bn (£596m, €734m) of exploratory work in a natural gas block in Peru, purchased from the Brazilian state-run oil firm.

More investment is expected, Gong Bencai, head of CNPC's Latin America division, told Reuters.

In particular, CNPC is eyeing a $4bn gas pipeline project in southern Peru, Gong said. The pipeline will transport natural gas from the Andean Camisea deposit to thermoelectric plants on Peru's Pacific coast.

"We are looking for more opportunities in Peru, to acquire companies or to participate in the bidding of oil fields," said Gong. "We are very interested in the southern pipeline."

In November 2013, PetroChina agreed to pay $2.6bn for Petrobras' Peruvian oil and gas assets, as part of a drive to meet rising energy needs in China, the world's second-largest and fast-growing economy.

The deal gave the Chinese firm access to three oil and gas fields in Peru producing about 800,000 tonnes of oil equivalent a year.

CNPC also has operations in Brazil, Colombia, Cuba, Costa Rica, Ecuador and in South America's biggest crude exporter Venezuela.