Woodside Petroleum last sold a March-loading Cossack cargo at below $1 a barrel premium to dated Brent, traders have said.

There were no spot Cossack cargoes available for export in April.

The premium for May-loading cargo is up likely due to non- availability of Kutubu Light cargoes, traders said.

Oil Search is yet to release its May-loading program for Kutubu Light oil cargoes following a powerful earthquake in Papua New Guinea in late February which knocked out ExxonMobil's LNG export facility.