HOUSTON (Reuters) - British oil major BP (>> BP plc) and China Oil have been awarded a tender launched by Venezuela's PDVSA to buy some 8 million barrels of Nigerian and U.S. light crude for delivery during the second quarter, traders told Reuters on Friday.

The deal, which will significantly increase PDVSA's crude purchases, could in exchange give BP access to Venezuelan oil to process or resell, while increasing the volume that Chinese firms take from PDVSA under loan-for-oil agreements.

China Oil, a unit of state-run China National Petroleum Corporation (CNPC), must deliver 2.7 million barrels of U.S. WTI crude in April at PDVSA's terminal in Curacao at a price of NYMEX WTI plus $1.58 per barrel, according to a Platts report published earlier on Friday.

For its part, BP must discharge 2.7 million barrels of WTI in April at a price of $2.39 per barrel over NYMEX WTI, and 2.7 million barrels of Nigeria's Qua Iboe crude in May-June at NYMEX futures plus $2.00 per barrel.

Deliveries of Venezuelan crude as payment for the U.S. and Nigerian cargoes will be allowed, according to the tender's terms.

Even with more flexible terms, which include prepaying the cargoes, cash-strapped PDVSA did not receive as many bids as in previous tenders, two sources from companies invited to the offer said.

Some firms that have sold oil to PDVSA since it started regular crude purchases in 2014 decided not to bid to avoid unpaid invoices, they added. Trading companies were not invited, another source said.

PDVSA did not respond to an information request. BP declined to comment on specific sales or customers.

Since a backlog of tankers formed in late 2015 due to payment delays to PDVSA's suppliers, the company faces challenges in doing businesses with its traditional providers.

But for those willing to take the risk, this tender and another to import up to 3 million barrels of Russia's Urals crude could allow them to regain or widen access to Venezuela's oil flows if they accept proposed swap deals.

Since it completed the sale of its stake in TNK-BP to Russia's Rosneft (>> Rosneft' NK OAO) in 2013, BP has not had frequent access to Venezuelan heavy crudes, which are very much in demand by refineries in the U.S. Gulf Coast.

BP, which has been actively buying WTI crude at Cushing, Oklahoma, is a regular seller of refined products to Venezuela.

Venezuela exports 1.8 million barrels per day and imports around 50,000 bpd of crude.

(Reporting by Marianna Parraga and Liz Hampton, Editing by Dan Grebler)

Stocks treated in this article : Rosneft' NK OAO, BP plc