* Shell completes $53 billion acquisition
* To become top LNG trader, major offshore oil producer
* Acquisition to define Shell CEO's legacy
By Ron Bousso
LONDON, Feb 15 (Reuters) - Royal Dutch Shell onMonday sealed the $53 billion (36 billion pounds) acquisition ofBritish rival BG Group to form the world's top liquefied naturalgas company, even as slumping oil prices cast a shadow on theupcoming years of transition.
The success or otherwise of the complex merger will definethe legacy of Shell Chief Executive Ben van Beurden, seeking totransform Shell into a more specialised group focused on therapidly growing LNG market and deepwater oil production.
"We will now be able to shape a simpler, leaner, morecompetitive company, focusing on our core expertise in deepwater and LNG," van Beurden said in a statement. In 2014, Shellacquired Repsol's LNG business.
Van Beurden's vision won overwhelming support fromshareholders, though a number of major investors had voicedconcerns that the forecast slow recovery in oil prices wouldstrain Shell's financials and risk its growth plans.
The deal, announced 10 months ago, creates a combined groupwhich will leapfrog Chevron to become the world'ssecond-largest public oil and gas company by market value behindExxon Mobil Corp.
BG shareholders largely opted to receive shares rather thancash under the proposed mix and match deal, according to astatement. BG becomes a wholly-owned subsidiary of Shell andwill be headed by Dutchman Huibert Vigeveno, who has headed theintegration planning team and will oversee itsimplementation.
SPECTACULAR GROWTH
Signs at BG's headquarters in Reading outside London werereplaced by Shell's red-and-orange logo over the weekend,according to company sources.
Incumbent CEO Helge Lund, former head of Norwegian oil majorStatoil who led it through a period of spectaculargrowth, is set to step down and has yet to indicate his plans.
Shell has said it will cut thousands of jobs from thecombined group and sell $30 billion of assets over the nextthree years in order to finance the deal, buy back shares andsupport dividends, which it has vowed to maintain or increase.
Shell is betting heavily on a rapid growth in the global LNGmarket over coming decades as the world turns to less pollutingsources of energy. Yet with oil prices near a 12-year low, astruggling global economy and major restructuring under way ofits oil and gas operations across the globe, the merger is setto be a challenge even for 126-year-old Anglo-Dutch company.
Shell saw its income drop 87 percent in 2015.
"The financials will work in time, admittedly perhaps not asoriginally hoped, but we still see this deal as accretive withina two- to three-year timeframe," said Jason Kenney, analyst atGrupo Santander, who estimates the acquisition will increaseShell's oil and gas production to around 4.7 million barrels ofoil equivalent by 2020.
"The deal means Shell will have little need to explore nearor medium term, or to invest in highly capital-intensiveunconventional projects," Kenney added. (Additional reporting by Karolin Schaps; Editing by DavidHolmes)