North Sea Crude-Forties diffs edge up; may turn positive

* Forties trades at 10 cents below dated Brent * Oseberg offers tumble on strong supplies GENEVA, April 19 (Reuters) - North Sea Forties crude pricedifferentials crept towards positive territory on Friday asrefinery restarts eclipsed strong production from the Buzzardoilfield. Improving refining margins have been the main factor behinda 20 cent rise in Forties differentials from this time lastweek, traders said. Differentials have traded at a discount todated Brent since early March. Total will restart its 230,000 bpd Doges refinery in thenext few days after planned maintenance, a plant union sourcesaid on Friday. Refining margins in northwest Europe have risen by around 40cents from an average of $5.46 a barrel in March, according toReuters data. "The market's definitely picking up as refiners add todemand and Forties may keep going," said a North Sea trader. Traders added that another supportive factor was fallingsupplies of west African crude oil in the region after Shelldeclared force majeure on its Nigerian Bonny Light crudeexports. But other North Sea grades including Oseberg were weaker onFriday as one trader said that sellers "struggled" to placeremaining cargoes for May. This grade is due to load 155,000 barrels per day in May, upfrom a planned 120,000 bpd in April. SPOT TRADE * Vitol sold a Forties cargo for loading May 11-13 to Shellat dated Brent minus 10 cents a barrel. This was up from thelast Forties deal on Tuesday at dated minus 58 cents. * Total was also a buyer in the publicly traded window onFriday and bid for a Forties cargo up to dated Brent minus 20cents. There was no matching offer. * Oseberg: Statoil offered an Oseberg cargo for loading16-31 May at dated plus $1.30 a barrel on Friday. This was down30 cents from the last level assessed by Reuters. SWAPS The swaps curve was as follows: 22-26/4 Jul -31 29-03/5 Jul -32 7-10/5 Jul -27 13-17/5 Jul -22 20-24/5 Jul -19 28-31/5 Jul -19 DATABASE