LONDON, Aug 20 (Reuters) - Ekofisk differentials slipped onMonday while sellers pitched Brent and Forties cargoes above thelast known traded levels, without tempting buyers.
In other developments, a one-day strike began at Totaloil and gas rigs and a trade source said that Shellplanned to load another Forties VLCC in August.
STRIKES
* Workers at three of Total's North Sea oil and gasplatforms started a 24-hour strike on Aug. 20 as scheduled, theUnite union said on Monday.
The three platforms are Alwyn, Elgin and Dunbar, whichaccount for about 10 percent of Britain's gas output and about45,000 to 50,000 barrels per day (bpd) of oil to the Forties andBrent streams.
VLCC MOVEMENTS
* Shell is loading Forties at Hound Point terminal on theVLCC Bukha on Aug. 31, a trade source said. That would bring thenumber of VLCCs being loaded in August to four, according toReuters shipping records, a relatively large number.
WINDOW SUMMARY
* No deals were done.
* Brent: Shell offered a cargo loading Sept. 6-8 at datedBrent plus 10 cents. That was higher than the last Reutersassessment of dated minus 80 cents.
* Forties: Glencore offered a ship-to-ship cargo from theMarbat, loading Aug. 30 to Sept. 7, at dated Brent plus 10cents. That was also up from the last assessment of dated minus80 cents.
* Ekofisk: Shell offered a Sept. 10-12 cargo at dated Brentplus 10 cents, down 5 cents from an offer on Friday.(Reporting by Alex LawlerEditing by David Goodman)