Traders said that slower demand from French refineries helped to prevent further strength, and market activity was very slow.
However strong gasoline and diesel refining margins helped support demand from refiners not affected by the strikes.
Oseberg was offered for a second day at the same differential.
WINDOW SUMMARY
Glencore offered an Oseberg cargo for loading June 14-16 at dated Brent plus $1.25, exactly in line with the offer the previous day.
That makes it equal to dated plus 34 cents when applying the June quality premium of 91 cents.
Unipec offered a cargo of Forties at dated Brent plus 40 cents. On Thursday it was assessed at Brent plus 5 cents, having weakened on Monday in response to offers of crude from floating storage.