U.S. WTI Midland crude differentials weakened on Friday after a lower offer, while North Sea differentials that help set the dated Brent price were steady after a lack of indications in the Platts window.

PLATTS WINDOW

* Indications are on a free-on-board (FOB) basis unless marked as cost, insurance and freight (CIF) or delivered at place (DAP).

* No deals, a trade source said.

* WTI Midland: BP and Shell both offered CIF Rotterdam cargoes at dated Brent plus $1.50 covering the Dec. 19-25 period.

* These were up 10 cents from an offer on Thursday, so the assessment remains steady at dated plus $1.35, equal to about dated Brent plus 5 cents on an FOB basis, according to Reuters calculations.

* Johan Sverdrup: Equinor offered Dec. 6-10 at dated Brent minus 85 cents. Sverdrup is not part of the Brent benchmark.

* WTI Midland is the cheapest grade in the Brent basket and the one that sets the dated Brent quote.
Source: Reuters (Reporting by Alex Lawler; Editing by Shilpi Majumdar)