* UK GDP +1.5 pct in Q2 year-on-year
* Sterling falls as data paints weak picture
* Current account deficit bigger than expected
* BoE's Carney sees rate hike in "relatively near term"
* UK house price growth weakest since 2013
* BoE says mortgage approvals fall
(Adds detail, wraps in BoE mortgage data and economists' reaction) LONDON, Sept 29 (Reuters) - Britain's economy grew at its slowest pace since 2013 in the 12 months after last year's Brexit vote, data showed on Friday, painting a subdued picture as the Bank of England prepares to raise interest rates for the first time in a decade. The world's fifth-biggest economy was just 1.5 percent bigger than a year earlier in the second quarter, the weakest year-on-year expansion in more than four years and down from a rate of 1.8 percent in the first three months of the year. Britain's Office for National Statistics had previously estimated second-quarter growth at 1.7 percent, and none of the economists polled by Reuters before the data had expected such a big downward revision. Friday's data also showed a monthly fall in output for the services sector in July, boding poorly for third-quarter growth. Sterling fell after the data and prompted some economists to reconsider their prediction of a rate hike at the end of the BoE's next meeting on Nov. 2. "I'm sticking to my call for a hike in November, but I'm much more nervous now than I was prior to this data release," Scotiabank's Alan Clarke wrote in a note to clients. However, the weak data might not stand in the way of the BoE raising interest rates from their record low 0.25 percent. BoE Governor Mark Carney said on Friday the economy was on track for a rate hike "in the relatively near term", two weeks after the BoE jolted markets by flagging a rate rise "in the coming months," despite weak growth this year. The BoE has downgraded its estimate of how fast Britain's economy can grow without generating excess inflation because of the impact of Brexit, so Friday's weaker growth picture is not necessarily fatal for the chances of a November rate rise.
REVISING THE PAST A major annual set of revisions of Britain's official data showed show stronger business investment, net exports and household savings, but also a larger current account deficit. Britain sucked in 23.2 billion pounds ($31.0 billion) of foreign finance in the three months to June, far above economists' 16 billion pound forecast, and the first-quarter deficit was revised up to 22.3 billion pounds from 16.9 billion. Business investment grew by an annual 2.5 percent in the second quarter, compared with an earlier estimate that it had stagnated, and households' savings ratio was a relatively healthy 5.4 percent in the second quarter. Net exports contributed 0.4 percentage points to quarterly growth, compared with earlier estimates of zero, and an inflationary squeeze on consumers may be easing, with real household disposable income up 1.6 percent in the latest quarter, the most since 2015. Nonetheless, the broader picture remains one of consumers under pressure from a steep rise in inflation caused by the fall in the pound since last year's Brexit vote. Disposable income has fallen year-on-year for the last four quarters, the longest period since 2011. Overall quarterly GDP growth was unrevised at 0.3 percent, and the services sector - which makes up 80 percent on the economy - contracted by 0.2 percent in July. Separately, mortgage lender Nationwide said house prices - a bellwether for consumer demand - rose at their slowest rate in four years this month, and the Bank of England said mortgage approvals fell in August. "It would be unprecedented for the central bank to tighten policy with the data pointing to such anaemic economic growth," Chris Williamson, chief economist at financial data company IHS Markit, said. "However, policymakers continue to fuel expectations that interest rates will rise soon in response to higher-than-expected inflation," he said. ($1 = 0.7485 pounds)
(Reporting by David Milliken; Editing by Toby Chopra)