* Q4 GDP fell 0.5 pct qq vs earlier estimate of 0.6 pct fall
* Weakest quarter for services and households since Q2 2009
* UK goods trade deficit biggest since records began in 1955
(Adds reaction, detail)
By David Milliken and Keith Weir
LONDON, March 29 (Reuters) - Britain's economy shrank slightly less than previously estimated at the end of 2010, but still suffered its biggest drop since 2009, according to data that underlines the uncertain nature of its recovery.
Tuesday's figures did not shift economists' view that first-quarter GDP data due next month will be the key to whether the Bank of England raises interest rates in the first half of this year, and illustrate the economy's vulnerability as the government embarks on a tough austerity programme.
The Office for National Statistics said gross domestic product (GDP) contracted by 0.5 percent in the last three months of 2010 -- the same as its initial estimate in January but a slightly smaller fall than a revised estimate made last month.
"It's still a pretty lacklustre backdrop and that probably sets the tone for the first half of this year," said Ross Walker, an economist at Royal Bank of Scotland.
Year-on-year, fourth-quarter GDP growth was unrevised at 1.5 percent, in line with economists' forecasts.
Share prices pared losses after the data, but there was little reaction from sterling or the government bond market.
"The figures generally have relatively few implications for monetary policy," said Philip Shaw, an economist at Investec. "Our view is that what's going to be very important is the retail figures over the next few months, and our readings of those trends is that they trend to argue against a May rate hike."
The ONS said that Britain's coldest December in 100 years had knocked 0.5 percentage points off national output, causing the biggest fall in GDP since the second quarter of 2009, and that growth would have been flat without the adverse weather.
The services sector and the construction sector both suffered their biggest contractions since the second quarter of 2009, when Britain's economy was deep in recession. Household expenditure also suffered its biggest fall since then.
Industrial output grew at its fastest pace since the second quarter of 2010, but this did not stop Britain recording its biggest goods trade deficit since records began in 1955.
The overall current account deficit totalled 2.9 percent of GDP in the fourth quarter, also the biggest since the second quarter of 2009.
(Editing by Ruth Pitchford)