* August retail sales +1.0 pct m/m vs +0.2 pct forecast Sterling jumps, 10-year gilt yields highest since Feb
* Retailer Kingfisher says sales of high-cost items steady
* BoE survey reports consumer weakness, peak of inflation effect
* OECD predicts UK growth will slow to 1.0 pct in 2018
(Adds fresh market and economist reaction) LONDON, Sept 20 (Reuters) - British retail sales unexpectedly surged in August, boosting chances the Bank of England will raise interest rates for the first time in a decade at its next meeting. More downbeat news, however, came from a BoE survey which showed no sign that wages were likely to grow much more quickly, tempering a jump in sterling. The Organisation for Economic Co-operation and Development, meanwhile, said uncertainty about Brexit meant Britain next year will suffer its slowest growth since the financial crisis. The contrasting signals underscored the challenge for the BoE which last week surprised investors by saying it was likely to raise rates in the coming months if the economy and inflation pressures strengthen as expected. That change of gear by the BoE came despite the uncertainty about Britain's withdrawal from the European Union and mixed messages about the strength of the economy. Wednesday's official data showed a sharp pick-up in monthly sales growth in August, despite inflation pressures that have previously squeezed spending. Retail sales volumes rose 1.0 percent month-on-month, their fastest since April, to give an annual growth of 2.4 percent, both well above the highest forecasts in a Reuters poll. More Britons holidaying at home and more foreign visitors, reflecting the weaker pound since the Brexit vote, could be behind some of the rise, economists said. Shoppers spent heavily on non-essentials, despite rising prices, with strong demand for watches and jewellery. "These latest figures will give further encouragement to the Bank of England to follow up their recent statements on the need to raise interest rates," Andrew Sentance, a former BoE policymaker who now advises accountants PwC, said. HSBC said market pricing for a quarter-point rate rise on Nov. 2, after the BoE's next meeting, rose to 65 percent. Sterling gained almost a cent against the U.S. dollar after the data, before later giving back most of its gains. British retail data is frequently volatile on a monthly basis and a separate survey released by the BoE on Wednesday offered a more downbeat picture. Construction and consumer-facing industries were suffering and there were mixed signals on investment, although factory exports and business-to-business services were strong. Pay rises mostly remained at 2-3 percent, below inflation but there were some signs that the worst of the impact on prices of last year's fall in the pound should start to ease.
INFLATION SQUEEZE PEAKING? The loss of disposable income this year caused the weakest first quarter for retail sales since 2010. But companies have reported little slowdown in spending so far.
Kingfisher , Britain's biggest home improvements
retailer, said sales of expensive power tools and new kitchens had not changed, though it was cautious about the outlook. The OECD said British growth will slow from 1.6 percent this year to 1.0 percent in 2018, weaker than the BoE and most economists expect. It would be the slowest growth since the 2009 recession. The BoE said last week that Brexit as well as longer-term problems mean the pace at which Britain's economy can grow without generating excessive inflation -- and requiring higher interest rates -- has fallen. HSBC economist Liz Martins said Wednesday's data raised the chance of stronger than expected growth, making a rate hike in November even more likely. "The Bank sounded comfortable enough about raising rates in November on an assumption of 0.3 percent growth in the third quarter. If the number is higher, then it will be even more." she said.
(Reporting by David Milliken and William Schomberg. Editing by Jeremy Gaunt)