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* British retailers embrace U.S. Black Friday discounts
* More shoppers head online after brawls in stores last year
* Sales boost jeopardises margins in crucial period (Adds Argos comment)
By James Davey and Li-mei Hoang
LONDON, Nov 27 (Reuters) - Britons splashed out on "BlackFriday" bargains on Friday but many opted to go online ratherthan head to the shops for an event imported from the UnitedStates that has become a key feature of the UK retail calendar.
With many shoppers having received their last pay packetbefore Christmas, retailers are hoping the promotions willkick-start festive trading after a weak November.
Researcher Conlumino is forecasting the event will generateUK sales, both in stores and online, of 1.6 billion pounds ($2.4billion), up 20 percent on 2014. It forecast online spendingwould jump 32 percent to 1.1 billion pounds.
"There's been plenty of anecdotal evidence around...tosuggest that Black Friday, in terms of store-based retail, hasbeen something of a damp squib in the UK this year," said BryanRoberts of researcher Kantar Retail.
"It seems certain that Black Friday will largely be anonline event this year."
Last year's Black Friday was marred by long queues andbrawls in stores. A typical mixture of strong winds and heavyrain across Britain and memories of last year's scuffles werelikely to have encouraged more Britons to shop online this year.
British retailers are anxious to avoid a repeat of lastyear's trading pattern when the surge in lower-margin sales wasfollowed by disappointing demand as shoppers held back in thehope of further discounts.
This year several retailers -- including Amazon,Argos, Marks & Spencer and Dixons Carphone -- have stretched "Black Friday" discounts over severaldays to smooth demand.
Social media indicated stores across the country werequieter than last year and shoppers better behaved.
Researcher FootFall estimates Black Friday in-store shoppernumbers will be down by up to 4 percent from 2014.
Supermarket Asda, which is owned by Wal-Mart and wasone of the UK's Black Friday pioneers, stepped back from theevent this year, blaming "shopper fatigue".
UNPRECEDENTED DEMAND ONLINE
At the huge Westfield shopping centre in east London, closeto the London 2012 Olympic stadium, trading was lively ratherthan frenzied.
Shaquille Simon, a 21 year-old McDonald's manager, said hebought two TVs online from Tesco at midnight: "I bought one forme and one for my mum. Why not?"
He then headed to Westfield, where he picked up speakers andheadphones. "If I see something I like I'll buy it. Simple asthat," he said.
In the U.S. Black Friday, the day after the Thanksgivingholiday, was so named because spending would pick up andretailers would begin to turn a profit for the year and moveinto the black.
Introduced into Britain in 2010 by U.S. online retailerAmazon, its popularity forced store groups to join the fray andthis year, according to a survey by Barclays, 77 percent of themare participating.
There was a similar trend in the United States where crowdswere relatively thin but online sales appeared strong.
Dixons Retail's Currys PC World chain reported unprecedentedonline demand, with a 53 percent increase in hourly web trafficcompared to last year. The firm's CEO Seb James tweeted:"Website holding up really well after big investment this year."
Social media reported that both Argos and Tesco's websiteswere struggling to keep up with demand.
Argos said its site had so far seen over 7.2 million visitsbut had not crashed or seen any outages. It apologised if somecustomers were experiencing delays as a result of demand.
Previous Black Friday winners in Britain have been thoseretailers, such as Dixons Retail, who buy specifically for theevent, enabling them to maintain profit margins.
Losers tend to be those who simply slash prices on existingstock or react to rivals' promotions. ($1 = 0.6616 pounds)
(Editing by Keith Weir)
