Sterling edges up vs dollar; focus on UK GDP data

* Sterling up 0.2 pct vs dollar at $1.6078 GBP=

* UK Q3 GDP seen revised to -0.1 pct vs -0.3 pct previously

* BoE's Posen: working on "plan B" if QE falls flat

LONDON, Dec 22 (Reuters) - Sterling edged higher against the dollar on Tuesday as the market awaited data which is expected to show the UK economy contracted by less than previously estimated in the third quarter.

The figures, due at 0930 GMT, are forecast to show a contraction of just 0.1 percent in the three months to September against the previous estimate of a 0.3 percent fall. ECONGB

Confirmation of an upward revision may give the pound a brief lift, but analysts said it is unlikely to alter the negative sentiment towards the currency due to the relatively weak UK economy and concerns over a ballooning fiscal deficit.

"The market expects the data to show a further modest revision to GDP. This would be a step in the right direction but it would still confirm that the UK is lagging the U.S. and the euro zone economies," said Geraldine Concagh, economist at AIB Group Treasury in Dublin.

By 0900 GMT, sterling was up 0.2 percent on the day at $1.6078 GBP=D4.

Despite rising on the day, it stayed not far from a low of $1.6030, its weakest since mid-October.

The pound dipped against the euro EURGBP=D4, which rose 0.1 percent to 89.10 pence.

Calyon's Daragh Maher said 200-day moving averages could be in focus for sterling, providing support for sterling/dollar at around $1.6010 while keeping euro/sterling propped up above 88.67 pence.

"The final estimate of UK GDP may see a modest upward revision but it is hard to see the market taking too much solace from this given they never really believed the first estimate in any case," he said in a note.

The market will also be wary ahead of Wednesday's release of the minutes to the Bank of England's December policy meeting. These will be eyed for any hints on the central bank's stance going forward after it left interest rates and its quantitative easing target unchanged.

The Bank of England's Adam Posen was quoted on Tuesday as saying Britain's fiscal and monetary policies were a success, but that it was working on a "Plan B" in case its quantitative easing fell flat. [ID:nLDE5BL0AD]

The Monetary Policy Committee (MPC) member told the Daily Mail the country was not facing a deflationary scenario, nor a Japan-style lost decade, but it "could be a slower few years". He also described sterling's fall as a sensible adjustment.

"The gloomy outlook for the UK economy remains little changed and the monetary policy prospects for the ECB and the BoE are likely to diverge some more in the near term before they start converging once again in coming months," Commerzbank analysts said in a note to clients.

"Against this backdrop, many investors are likely to use any fundamental disappointments today to take profit on their long pound positions," they said.

In other news, the Royal Institution of Chartered Surveyors said British house prices will rise by 1-2 percent next year, with gains in the first few months of 2010 followed by stagnation and modest falls in the second half of the year. [ID:nLDE5BK0X3] (Reporting by Jessica Mortimer; editing by Stephen Nisbet)