LONDON, Dec 19 (Reuters) - North Sea Forties crude was again on offer in the Platts window on Friday, but at slightly firmer levels than where ExxonMobil XOM.N was seeking buyers the previous day.

PLATTS WINDOW

• Indications are free on board (FOB) unless marked as cost, insurance and freight $(CIF)$ or delivered at place (DAP).

• No deals, a trade source said.

• Forties: There were three offers by ExxonMobil, for January 9-11 at dated Brent plus 81 cents, January 12-14 at dated plus 82 cents, and January 4-6 at dated plus 75 cents.

• In the previous session, Exxon offered at dated Brent plus 70 cents for January 3-5.

• There was no fresh window activity for Brent, Ekofisk, Oseberg, Troll or WTI Midland on Friday.

• Johan Sverdrup: Equinor bid at dated Brent minus $1.10 for a January 1-8 cargo.

• Johan Sverdrup is not one of the grades that underpins the dated Brent benchmark.

(Reporting by Robert Harvey; Editing by Shailesh Kuber)

((Robert.Harvey@thomsonreuters.com))