* Oil major buys various grades from Qatar, UAE, Russia
* Big volume purchase tightens spot market in Asia
* Shell re-sells Qatar Marine and Sokol
By Florence Tan
SINGAPORE, April 20 (Reuters) - Royal Dutch Shellhas snapped up more than 8 million barrels of Middle East andRussian crude oil loading in June and resold some cargoes athigher premiums as it profits from robust demand in Asia, fivetrading sources said on Friday.
The region's pull on Middle East and Russian grades, pricedoff Middle East crude benchmark Dubai, has strengthened thismonth as a widening of Brent's premium to Dubai has madecompeting Atlantic Basin supplies more expensive.<DUB-EFS-1M>
Asia's crude demand is also set to rise in the third quarteras refiners return from maintenance to ramp up output to meetpeak summer oil consumption.
Shell has bought six June-loading cargoes of Qatar Marine,four cargoes of Upper Zakum and three cargoes of Russian Sokolcrude from various market players, two sources directly involvedin the trades said.
The oil major has also purchased at least a cargo each ofBanoco Arab Medium and al-Shaheen crude, they said.
Each cargo of Middle East crude is about 500,000 barrelswhile a Sokol cargo is 700,000 barrels. The company has theoption of re-selling some of the crude or can send the oil toits refineries.
Shell said it does not comment on details of commercialagreements or the movement of cargoes.
Shell's purchases have reduced the availability of spotcargoes in the market, leaving the oil major as the sole sellerfor some grades, the sources said.
Shell has resold one of the Qatar Marine cargoes to a Thaiend-user at a premium of more than 20 cents a barrel to thecrude's official selling price, versus earlier deals at premiumsof 10-20 cents, they said.
(Reporting by Florence Tan; editing by Richard Pullin)