UPDATE 5-Carney signals earlier British rate rise, sterling soars
* Carney says rates may rise earlier than markets expect
* Sterling nears five-year high against dollar on comments
* Carney says rate increases would still be gradual
* Reuters poll shows UK rate rise likely in Q1 2015
* S&P revises UK AAA rating outlook up to stable (Adds Standard & Poor's rating outlook upgrade)
LONDON, June 13 (Reuters) - Britain could become the first major economy to tighten monetary policy since the 2008 financial crisis, Bank of England Governor Mark Carney has signalled, sending sterling shooting towards a five-year high against the dollar on Friday.
British government bond yields soared, construction stocks tumbled and interest rate futures priced in a first hike by December after Carney said rates could rise sooner than markets had thought - his most hawkish comment to date.
"There's already great speculation about the exact timing of the first rate hike and this decision is becoming more balanced," Carney said in a speech late on Thursday alongside British finance minister George Osborne.
"It could happen sooner than markets currently expect."
Few economists had expected rates to increase until the second quarter of next year given the central bank's previous guidance that there was plenty of scope for Britain's economy to expand further without causing inflation.
A Reuters poll of economists on Friday showed most expect a rate rise will come by March 2015, three months earlier than a previous poll published two weeks ago. Only a minority expect a rate rise before the end of this year.
A rise in BoE rates this year would be the first since 2007 and put it ahead of both the U.S. Federal Reserve and the European Central Bank. The Fed is still pumping extra stimulus into the U.S. economy while the ECB cut interest rates to record lows last week and said it may not have finished easing.
Carney said Britain's economy still had room to grow without pushing up inflation, but added that he saw little sign yet of a slowdown in the pace of expansion that the central bank had pencilled in for the second half of the year.
"The change reflects the reality in the economy. It is flying now. Employment is rising at a record pace and we see no sign of economic growth slowing from its current pace," said Rob Wood, chief UK economist at German bank Berenberg.
The pound hit a 5-1/2 year high against a trade-weighted basket of currencies and came with in a hair's breadth of its highest in almost five years against the dollar.
Short sterling rate futures fell <0#FSS:>, pricing in the first hike by December. The interbank interest rate curve (SONIA) also pointed to a rate rise by year's end. On Thursday it had pointed to a rise in the first quarter of 2015.
Rating's agency Standard & Poor's upgraded its outlook for Britain's triple-A credit rating to stable from negative late on Friday, although rivals Moody's and Fitch have still kept it a notch below triple-A.
An interest rate rise before a national election next May could hurt perceptions of the Conservative-led coalition government by raising mortgage costs and eating into disposable income, which the opposition Labour party says is being eroded by rising prices for everything from energy to transport.
"It is absolutely without question that those people who are right on the edge at the moment will, with a small increase in interest rates, be pushed over the edge," Conservative lawmaker Mark Garnier told Reuters.
HITTING VOTERS IN THE POCKET?
Although Britain's $2.5 trillion economy has won back the output lost in the convulsions of the 2008 crisis, Garnier said it could be a hard sell to convince voters of the recovery if they felt they had less money in their pockets.
"We can't just go to people and say: 'Yes, it's costing you more, but overall the economy is bigger'. They'll just turn around and say 'Well, it's not bigger for me'," he said.
While Britain's economy is growing fast now, its recovery began much later than in the United States or Germany, and wages have fallen significantly in real terms since the financial crisis.
Carney also said the central bank would weigh carefully the merits of tackling housing market risks, including an undesirable loosening in mortgage underwriting standards, when its Financial Policy Committee meets later this month.
House prices in London have soared in the past year and though rises outside the capital have been more modest, Carney cautioned that average household debt was 140 percent of disposable income - higher than in most other countries.
Osborne said he would grant the BoE new powers to impose maximum loan-to-value and loan-to-income ratios on mortgage lending, a step which Carney welcomed.
Last month, a minority of BoE policymakers said the case for a rate rise was "more balanced" and that interest rates might need to increase sooner rather than later to ensure they did not need to rise sharply.
But Carney had until now appeared less keen to contemplate tightening, emphasising that Britain's economy was still a long way from full strength.
On Thursday, he said that more important than the timing of a first rate rise was that future increases be "gradual and limited", in part due to high household indebtedness and a drag on growth from a stronger currency.
He also said the timing of a rise would depend on incoming data, and the bank had no fixed plan on when to raise rates. (Writing by David Milliken and Guy Faulconbridge; Additional reporting by Kate Holton, William James, Andy Bruce, Anirban Nag and Tricia Wright; Editing by Paul Taylor and Peter Graff)