* FTSE down 0.3 percent
* Miners pressured by weaker metal prices, banks sag
* Defensive stocks gain ground
By Simon Falush
LONDON, April 13 (Reuters) - Britain's top share index retreated by midday on Tuesday, weighed by weaker miners as metal prices fell, while banks also retreated on investor caution ahead of first-quarter results in the United States.
By 1056 GMT the FTSE 100 <
> was 19.22 points, or 0.3 percent lower at 5,758.43, having gained 6.67 points or 0.1 percent on Monday.Miners were the biggest drag on the index, dented by softer metal prices as uncertainty on the demand outlook held sway, while results from U.S. aluminium group Alcoa <AA.N>, released overnight, were in-line on earnings but light on revenues.
Xstrata <XTA.L>, Lonmin <LMI.L>, Anglo American <AAL.L>, Kazakhmys <KAZ.L> and BHP Billiton <BLT.L> fell 0.2-2.3 percent.
Tech bellwether Intel Corp <INTC.O> will release first-quarter numbers later in the day, while other major U.S. companies due to report results this week include JPMorgan Chase <JPM.N>, Google <GOOG.O>, Bank of America <BAC.N> and General Electric <GE.N>.
"All we need is a couple of disappointing results and as the market is looking quite overbought, we could see fairly sharp falls," said Nick Serff, market analyst at City Index.
Investor nerves on Greek debt problems also undermined sentiment although it easily sold a total of 1.2 billion euros ($1.63 billion) of 6-month and one-year T-bills, with bond fund Pimco saying it would not be buying new Greek debt as a euro zone rescue package fails to tackle the country's longer-term solvency challenges.
"The Greek situation is casting a shadow over things," Serff said.
Banks were mostly lower as investors trimmed holdings in assets they perceived as relatively risky ahead of U.S. results, with the Greek debt problems also weighing the sector.
Standard Chartered <STAN.L>, Barclays <BARC.L>, HSBC <HSBA.L> and Lloyds Banking Group <LLOY.L> fell 0.3-1.1 percent.
HIGH SPIRITS
Drinks producer Diageo <DGE.L> gained 1.8 percent, supported after luxury goods company LVMH <LVMH.PA> reported strong quarterly sales from its wine and spirits division. French peer Pernod Ricard <PERP.PA> was also stronger.
Other defensive stocks were in favour too as investors sought positions in lower risk assets. Pharmaceuticals firms AstraZeneca <AZN.L> and GlaxoSmithKline <GSK.L> added 0.2 and 0.7 percent respectively.
Department store group Debenhams <DEB.L> was among the top mid cap losers, down 2.3 percent although it beat forecasts with an 18.6 percent rise in first-half profits, with some analysts saying that current trading looked less positive.
But other retailers were higher, with Kingfisher <KGF.L>, Next <NXT.L>, Home Retail Group <HOME.L> and Marks & Spencer <MKS.L> ahead 0.5 to 2.6 percent, following an upbeat British Retail Consortium survey.
British retail sales rose at their fastest pace in a year in March but the figures were flattered by the earlier timing of Easter this year, the BRC said. [
]Also signalling an improved economic outlook, Britain's trade deficit narrowed to 6.179 billion pounds ($9.49 billion) in February, its smallest since June 2006, after exports rebounded strongly from weather-related weakness in January. [
]Meanwhile the Royal Institution of Chartered Surveyors said British house prices grew last month at their slowest pace since July after the amount of new property coming on to the market grew faster than the number of new buyers. [
]No significant U.S. economic data is due for release on Tuesday. (Editing by Rupert Winchester)