UPDATE 1-Bargains and brawls: "Black Friday" comes to Britain

(Adds detail, analyst comment)

By James Davey and Liisa Tuhkanen

LONDON, Nov 28 (Reuters) - British police officers werecalled to stores across the country on Friday as the "BlackFriday" shopping frenzy imported from the United States broughtsurging crowds and fights over sharply discounted goods.

For the first time, most British retailers have fullyembraced "Black Friday" promotions this year, both in store andonline, seeking to follow their cousins across the Atlantic andkickstart trading early in the key Christmas period.

The day after the U.S. Thanksgiving holiday, which falls onthe fourth Thursday of November, is extravagantly promoted inthe United States as the start of the Christmas shopping season.The surge in spending is said to make it the day when retailersfinally show a profit for the year, or go "into the black".

With no national holiday in late November, people in Britainhad no reason to notice the day until American online retailerAmazon brought its Black Friday sales across theAtlantic in 2010.

Last year marked the first time major UK store groups suchas John Lewis, Dixons and Wal-Mart's Asdaparticipated in a serious way, and this year has seen the trendexplode across a majority of the British retail sector.

A survey commissioned by Barclays found that 65 percent ofBritish retailers that sell both online and in stores plannedBlack Friday promotions.

Supermarket leader Tesco, clothing retailer Marks &Spencer, and electricals retailers Dixons and Argos are doing far bigger promotions than before. Others,like No 3 grocer Sainsbury's are participating for thefirst time.

The trend is also emerging in continental Europe, withSpanish department store El Corte Ingles using the term "BlackFriday", in English, to advertise price cuts and promotionsappearing in France and Denmark.

Police were called in to control crowds that had gatheredovernight in London, Manchester, Cardiff and Glasgow, drawn bycheap televisions, kitchen goods and clothes. Three arrests weremade at Tesco stores in Manchester and officers werecalled out to four others in the area.

"The events of last night were totally predictable and I amdisappointed that stores did not have sufficient security staffon duty," Chief Constable of Greater Manchester Peter Fahy said.

Queues started forming at Asda's superstore at Wembley,north London, from 0500 GMT. Its doors opened at 0800 GMT and by0900 many of the best bargains had gone.

"There was a fight in the queue in front of us," saidshopper Kristina Butts, 44, who missed out on the Polaroid 40inch TV and Xbox bundle she was after.

When the last of the TVs discounted by 50 percent to 299pounds ($469) was sold, a staff member held it up and shouted:"When it's gone, it's gone."

One woman shopper on a mobility scooter drove away from thestore shouting: "I will never do this again."

Whether embracing Black Friday makes commercial sense for UKretailers remains open to debate.

"All Black Friday is likely to do is bring forward businessfrom December, reduce gross margins and undermine consumers'willingness to pay full-price again before Christmas," saidindependent retail analyst Nick Bubb. Retailers that were notinvolved, like clothing retailer Next, were "thinkinglong-term and preserving their pricing power", Bubb said.

Asda argues it can protect profit margins by leveraging thehuge global purchasing power of its giant American parentWal-Mart. Dixons says it can maintain margins by placingespecially large orders with suppliers so it can securefavourable terms.(1 US dollar = 0.6370 British pound) (Additional reporting by Liz O'Leary and Teis Jensen; Editingby Peter Graff)