By David Milliken and William Schomberg

LONDON (Reuters) - British inflation unexpectedly held steady in August despite a big rise in the cost of imported raw materials after June's vote to leave the European Union, keeping the prospect of another Bank of England rate cut in play.

Consumer price inflation stayed unchanged at 0.6 percent, a contrast to fuel and material costs for factories which rose at their fastest rate in nearly five years, up 7.6 percent on a year earlier, official figures showed on Tuesday.

Economists said inflation was unlikely to resist pressure from sterling's 10 percent post-referendum fall for long.

"Despite this downside surprise ... we still see signs that inflation is pushing higher," Elizabeth Martins at HSBC said, citing the biggest monthly rise in food prices in 2-1/2 years and rising transport costs after 18 months of deflation.

Economists polled by Reuters had mostly expected inflation to edge up to a 21-month high of 0.7 percent.

Sterling fell around 0.6 percent against the dollar <GBP=> after the data, hitting a low of $1.3250.

"Raw material costs have risen for the second month running, partly due to the falling value of the pound, though there is little sign of this feeding through to consumer prices yet," ONS statistician Mike Prestwood said

Inflation last month was lower than the BoE's estimate of 0.8 percent, giving it confidence to press ahead with a new rate cut in November, Pantheon Macroeconomics's Samuel Tombs said.

"Above-target inflation in 2017, however, likely will ensure that the (BoE) holds back from additional government bond purchases next year," he added.

Last month the Bank cut rates for the first time since 2009 and restarted its quantitative easing program. It also said most policymakers expected to cut rates again this year.

Signs of a quick bounce back in the economy since then has caused some economists to question the chances of a further rate cut, especially as the BoE expects inflation to overshoot its 2 percent target later next year and in 2018.

Lower prices for clothing, hotels and wine kept inflation down in August, offsetting an upward effect from fuel prices, food and airfares. Core consumer price inflation, excluding food and energy costs, unexpectedly held steady at 1.3 percent.

The ONS data showed manufacturers' input costs jumped by the largest amount since December 2011, led by an 18.9 percent rise in the cost of imported metal. But factories raised the prices they charged by just 0.8 percent, less than economists expected, though still the biggest increase since January 2014.

HSBC's Martins said this was unlikely to last. "We believe that, in spite of the slowdown in the economy, there is scope for some of these higher costs to be passed onto consumers."

Annual house price inflation, which is not included in the CPI index, eased to a four-month low of 8.3 percent in July.

(Editing by Catherine Evans)