* Banks cautious ahead of British fourth-quarter GDP data
* Integrated oils rally, led by BG Group
* Diageo lifted by further positive broker comment
LONDON, Jan 25 (Reuters) - Britain's top share index was flat in early trading on Tuesday, pegged back by weakness in heavyweight banks and with caution prevalent ahead of GDP data due at 0930 GMT.
At 0904 GMT, the FTSE 100 index was 1.28 points higher at 5,942.57, having added 0.8 percent on Monday.
"Everyone is waiting for the GDP data with, on the first anniversary of Britain moving out of recession, growing fears that clear signs could be seen of a potential double-dip move," said Mic Mills, head of electronic dealing for ETX Capital.
Banks were the biggest drag on blue chip sentiment early on, as investors fretted over the strength of the economy, with part-nationalised lender Lloyds Banking Group the worst off, down 1.5 percent.
Economic growth in Britain likely slowed in the final three months of last year, with fourth-quarter GDP forecast at 0.5 percent, down from 0.7 percent in the third quarter.
A weak figure will reinforce concerns about whether economic recovery will be sustained when the government accelerates a programme of deep public spending cuts.
The Bank of England's Monetary Policy Committee now needs to focus on its main inflation objective, and not worry too much about trying to forecast growth, BoE policymaker Andrew Sentance said on Monday.
Global lender HSBC, however, bucked the bank sector trend, adding 0.1 percent. New chief executive, Stuart Gulliver, has dropped plans to relocate to Hong Kong and will stay in London, the Financial Times reported. Weak miners were also a drag on blue-chip sentiment, with Randgold Resources and African Barrick Gold among the worst off, down 1.5 percent and 1.0 percent respectively, as the price of gold hit a 10-week low.
Precious metals processor Johnson Matthey rallied, up 1.4 percent, helped by improving sales trends in the automotive industry for which it manufactures catalytic convertors, traders said.
Automotive parts maker GKN was the top blue-chip riser, up 2.0 percent, helped by above-forecast results from German group Siemens.
ENERGY BOOST
Strength in energy stocks provided underlying strength for the blue-chip index, with BP and Royal Dutch Shell up 0.4 percent and 0.1 percent respectively as the crude price stabilised after recent falls.
BG Group added 0.6 percent. The company is to invest $10 billion in Brazil over the next decade as it seeks to accelerate development of the country's deepwater oil fields, the Daily Telegraph reported.
Among individual gainers, drinks group Diageo took on 1.4 percent supported by further positive broker comment and figures for the U.S. spirits industry.
Morgan Stanley raised its target price for Diageo, with Exane BNP Paribas having done the same on Monday.
Market heavyweight Vodafone firmed 0.1 percent.
Gerard Kleisterlee, chief executive of Dutch electronics company Philips was seen as the favourite to become the next chairman of the British mobile phones operator, the Financial Times reported.
"Kleisterlee certainly has a strong background and pedigree for the chairman of Vodafone," said Atif Latif, director of trading for Guardian Stockbrokers. (Editing by Dan Lalor)