"We're about to firm up ONGC's financing to the joint venture we have in the San Cristobal field," Eulogio Del Pino, who is also Venezuela's Oil Minister, told Reuters.

He said the deal, which has been under negotiation for months, would be signed "soon."

The funds would go towards shoring up production at San Cristobal, which has fallen from a peak of over 40,000 barrels per day to around 28,000 bpd.

The deal is expected to ensure state-owned ONGC gradually receives around $530 million of unpaid dividends, though it could take years for the entire amount to be repaid.

The investment is also likely to involve the creation of an offshore account, probably in Asia, to receive the export income.

It was not immediately possible to get a comment from ONGC, India's largest oil and gas explorer.

The deal would come on the heels of last week's announcement that Russia's top oil producer, Rosneft, will invest $500 million as it raises its stake in the Petromonagas joint venture in Venezuela's Orinoco Belt region to 40%.

Fresh investment could help Venezuela, home of the world's largest crude reserves, shore up oil output.

ONGC Videsh, ONGC's overseas investment arm, has a 40% stake in the San Cristobal oilfield.

PDVSA subsidiary CVP has the rest.