* FTSE down 1.6 percent
* Energy, mining stocks slide on gloomy demand outlook
* Banks fall broadly; Stanchart gains
* Heavyweight pharmas rally
By Simon Falush
LONDON, March 3 (Reuters) - Britain's top share index was down 1.6 percent by midday on Tuesday, plumbing a fresh six-year low as anxiety about the outlook for the ailing financial sector and broader economy intensified, leading investors to dump equities.
By 1152 GMT, the FTSE 100 <
> had fallen 59.20 points to 3,566.63, after tumbling 5.3 percent the previous day. The index is down 19.6 percent this year after tumbling more than 31 percent in 2008, its worst year since the index was launched in 1984.The blue-chip index tumbled by more than 5 percent the previous session as a deep-discount rights issue and a huge quarterly loss from AIG spooked investors, already nervous about an ailing financial sector.
"The prevailing uncertainty surrounding the financial sector, including the banks and life insurers, remains a concern which is exacerbated by the likes of the HSBC news yesterday and the AIG loss. Against that backdrop it's difficult see a sustained rally in the short term," said Tim Whitehead, a stockbroker at Redmayne-Bentley.
After an early rally, fear once again gripped the market, and prices fell as investors sought safety in cash and gold.
Energy stocks took the most points from the index as gloom on prospects for oil tarnished the sector.
BP <BP.L>, Royal Dutch Shell <RDSa.L>, BG Group <BG.L> and Tullow Oil <TLW.L> fell between 1.8 percent and 3.9 percent.
Miners were also broadly weaker despite a slight recovery in metals stocks.
Xstrata <XTA.L> fell 7.7 percent with the stock trading ex-rights, while Rio Tinto <RIO.L> fell 4.3 percent and Antofagasta <ANTO.L> lost 4.1 percent.
Banks were also deeply in the red once again as jitters on the sector returned wiping away early gains, after Standard Chartered <STAN.L> announced its 2008 profits before tax were up 19 percent at $4.8 billion. Standard Chartered gained 1.5 percent.
Barclays <BARC.L> slid 5.9 percent with Nomura highlighting a short position on concerns about how the bank will fund joining the UK's asset purchase scheme, while Lloyds <LLOY.L> fell 5.7 percent and Royal Bank of Scotland <RBS.L> lost 5.8 percent.
The FTSE 350 banking index <.FTNMX8350> was down 2.4 percent. It has tumbled 43 percent this year after having slumped by almost 57 percent in 2008.
Adding to the gloom, data emphasised the bleak outlook for the economy. Activity in Britain's construction sector shrank at a record pace in February, a purchasing managers' survey showed. [
]"The data releases have done damage. If you look for a reason for a turnaround this is probably it," said Robin Evans, global strategist at Fox-Pitt, Kelton.
Heavyweight pharmaceuticals stocks Astrazeneca <AZN.L> and GlaxoSmithKline <GSK.L> were both up 1.8 percent as investors sought safety in defensive stocks.
Insurers managed to eke out gains, with Admiral <ADML.L> adding 2.2 percent after it reported an 11 percent increase in 2008 profits and Amlin <AML.L> gaining 3.4 percent to top the list of large-cap winners after Citigroup raised its price target.
Finance minister Alistair Darling told the Daily Telegraph that the Bank of England could start to buy assets this week with newly created money to boost both the money supply and the economy. [
]Britain is also due to unveil a financial support package to kickstart infrastructure projects that have been put on hold because of the credit crunch, sources familiar with the situation told Reuters. [
]Wolseley <WOS.L> fell 5.3 percent after the Financial Times said the building supplies group was planning to launch a 1 billion-pound rights issue that could come as soon as the end of next week.
U.S. Federal Reserve Chairman Ben Bernanke is due to testify on the economic outlook and the budget situation before the Senate Budget Committee at 1500 GMT. (Additional reporting by Martina Fuchs; editing by Karen Foster)