NSea Crude-Forties firmer on improved demand

* Forties firmer: deal at dated minus 25 cents for Nov 28-30

* Vitol keeps another cargo from chains; holds on to 7

* Statoil offers six new cargoes for December

LONDON, Nov 17 (Reuters) - North Sea Forties differentials
strengthened slightly on Tuesday, supported by improved demand
and as Vitol tightened the January Forties market.

FORTIES FOT-E

Within the afternoon trading window, Vitol sold Statoil a
Nov 28-30 loading cargo at dated minus 25 cents. This is firmer
than the last reported Forties deal on Friday when Conoco sold
its Nov. 26-28 cargo to BP at dated minus 35 cents.

* Vitol again kept an early-December loading cargo of
Forties from the chains, bringing the number of cargoes the
trader has held on to so far to seven.

Traders said Vitol could be preparing to take delivery of
the Forties cargoes, possibly to put it into floating storage as
the discount for prompt physical oil is undermined by
deteriorating refining margins.

NORWEGIAN GRADES

* Statoil indicated six cargoes on Tuesday:

- Oseberg loading Dec 12 at dated plus 90 cents

- Oseberg loading Dec 15 at dated plus $1.00

- Statfjord loading Dec. 17 at dated plus 65 cents

- Gullfaks loading Dec 13 at dated plus $1.25

- Gullfaks loading Dec 16 at dated plus $1.35

- Grane loading Dec 13 at dated minus 40 cents

REFINING MARGINS <REF/MARGIN1>

* Complex refining margins for North Sea Brent in Rotterdam
slipped to around $2.49 on Tuesday, down from an average over
the past five days of $3.50, according to Reuters models.

SWAPS

* Contracts for Differences (CFDs) continued to show
backwardation for nearby physical barrels (previous day in
brackets) as follows:

23-27/11 Jan -116 (-110)

30-04/12 Jan -94 (-91)

7-11/12 Jan -76 (-74)

14-18/12 Jan -58 (-57)

21-24/12 Jan -40 (-40)

29-31/12 Jan -24

ICE BRENT MARKER

* The ICE set its afternoon one-minute marker for January
Brent at $78.39 per barrel on Tuesday.

(Reporting by Joe Brock; editing by Sue Thomas)