LONDON, Sept 2 (Reuters) -North Sea Ekofisk crude was offered lower on Monday while U.S. WTI Midland was again steady due to a lack of buying interest at higher offer levels.

PLATTS WINDOW

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

* Ekofisk: Shell offered Oct. 2-4 at dated Brent plus $3.15, down from the last assessment.

* WTI Midland: Glencore offered CIF Rotterdam Sept. 17-21 at dated Brent plus $2.90, higher than Thursday's value of dated plus $2.75.

* In the absence of higher bids, WTI Midland's value is steady at dated Brent plus $2.75, equal to around dated plus $1.84 on a FOB equivalent basis, Reuters calculations showed.

* WTI remained the cheapest grade underpinning the benchmark on Monday.

Reporting by Alex Lawler, Editing by Tomasz Janowski

 NORTH SEA CRUDE OIL DIFFERENTIALS AND OUTRIGHT PRICES: 0#BFO-DIF 0#C-E Dated BFO BFO- Brent BFO-BRT BFO-E Forties BFO-FOT FOT-E Oseberg BFO-OSE OSE-E Ekofisk BFO-EKO EKO-E Monthly North Sea crude loading programmes O/LOAD OPEC OPEC NSEA North Sea CRU crude oil PROD oil products DRV derivatives PRO/E European products OILOIL NYMOIL, IPEOIL, OILSPD, OILARB CRDWLDPRODEUR, PRODUS, APROD ENERGY energy speed guide CRUDE/1 crude speed guide