Rosneft plans to invest another $500 million as it raises its stake in the Petromonagas joint venture in Venezuela’s Orinoco Belt region to 40 percent, President Nicolas Maduro said on Feb. 19.

That is the maximum stake foreign partners are allowed to hold in joint ventures with Venezuelan state oil firm PDVSA.

“Today we are going to sign (for) an additional investment of $500 million in the Orinoco belt from Rosneft which is going to raise its participation up to 40 percent,” Maduro said in comments broadcast live from the region.

Further details were not immediately available.

Rosneft originally had a 16.7 percent stake in the Petromonagas venture.

Reuters reported last June that PDVSA and the Russian oil major were negotiating a financing deal under which Rosneft would lend its South American counterpart $5 billion, a source close to the negotiations said.