Bids and offers emerged in the daily trading window for Norwegian grade Troll, which will be used to assess dated Brent from January, but no deals took place.
Troll was offered at a premium of $1.15 to the dated Brent price, above those for Oseberg, usually the most expensive of the four major North Sea grades, which was bid at a premium of 85 cents to dated Brent.
The amount of crude being stored on ships in the North Sea is rising again, after seemingly starting to drain last week, according to Reuters shipping data on Tuesday.
Based on Reuters calculations, there are now nearly 11 million barrels of crude offshore, almost double the amount on board ships this time last week.
There are at least three VLCCs holding Forties currently at anchor - the Desimi, the Boston and the Gener8 Neptune - all of which are holding Forties.
The Boston, which has been chartered by Total, has been at anchor at Southwold for at least a week, while the Gener8 Neptune, which loaded at Hound Point late last week, is currently due to discharge in Rotterdam. Both were scheduled to sail to Asia.