Abu Dhabi National Oil Co (Adnoc) has sold about 125,000 tonnes of naphtha to Vitol at premiums that were at least $10 below the market rate of $28 a tonne to Middle East quotes on a free-on-board (FOB) basis, traders said on Friday.

This was Adnoc's first naphtha spot sale after the expansion of its Ruwais refinery, where capacity has been more than doubled to over 800,000 barrels-per-day (bpd), they added.

Traders said refiners usually need time to fine-tune their oil products specifications when new units come onstream, and it was common for them to sell their first batch of cargoes at low prices to attract buyers.

"It is also not easy to load 125,000 tonnes of naphtha at one go," said a trader. Long-range vessels typically load 50,000 tonnes to 75,000 tonnes.

This would be the firm's largest single spot tender in terms of volume. Shipment is scheduled for mid-April from Ruwais, the traders said.

The news of the sale, however, could not be confirmed as Adnoc and its buyers do not usually comment on their deals.

No further details were available on the exact price fetched by Adnoc for the naphtha.

Traders estimated that premiums were likely more than $9 a tonne but below the $28 benchmark set by India's Oil & Natural Gas Corp and its unit Mangalore Refinery Petroleum this week after they sold two April spot cargoes.

Adnoc's Ruwais refinery expansion and expectations that, as a result, its naphtha exports would climb to over 10 million tonnes a year from about 7.5 million tonnes in 2014, has kept naphtha prices in check over the last few weeks. - Reuters