LONDON, July 5 (Reuters) -Norwegian flagship Johan Sverdrup crude differentials edged lower in the week's final trading session, while North Sea producers digested news of a Labour party victory in the UK general election.

UK ELECTION

* North Sea oil and gas producers urged Britain's incoming Prime Minister Keir Starmer to provide clarity on his election promise to increase tax on the sector, warning it could lead to a rapid decline in output and revenue.

PLATTS WINDOW

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

* Johan Sverdrup: Equinor offered a cargo loading on July 21-23 at dated Brent plus 95 cents, but no buyers stepped in to lift the offer.

* Equinor last offered Sverdrup on Monday, showing a July 18-20 cargo at dated plus $1.30.

* No deals, offers or bids appeared for any of the grades underpinning the dated Brent benchmark in the trading window on Friday.

* On Wednesday, Chevron bought from Exxon Mobil a July 27-31 cargo of WTI Midland at dated Brent plus $1.55 CIF Rotterdam, equating to about dated plus 51 cents FOB, Reuters calculations showed.

Reporting by Robert Harvey, Editing by Louise Heavens

 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