Brazil’s state-run oil producer Petrobras signed a US$3.5-billion financing deal with state-run China Development Bank.

The Brazilian company said in a regulatory filing on Wednesday that the deal was part of a co-operation agreement covering 2015 and 2016.

“Both parties confirmed their intention to work on further co-operation in the near future,” the Rio de Janeiro-based company said. “This contract is an important framework to continue the strategic partnership between China Development Bank and Petrobras.”

China Development Bank and Petrobras had already signed a US$10 billion cash-for-oil agreement in 2009.

Two Chinese state-owned oil companies, China National Offshore Oil Corp (CNOOC) and PetroChina Co, bought a 10-percent stake each in a consortium to explore Brazil’s biggest offshore oil field in 2013.