* FTSE 100 down 4 pct, touches 5-1/2 year low
* Miners, energy stocks hit by falling commodity prices
* Banks bruised by intensifying financial crisis (For more on the financial crisis, click on [
])
By Simon Falush
LONDON, Oct 27 (Reuters) - Britain's top share index slid by 4 percent by midday on Monday, as increasing anxiety about the state of the global economy hit embattled banks and demand worries sent energy and mining stocks tumbling.
By 1120 GMT the FTSE 100 <
> was down 152.89 points at 3,730.47, having earlier touched a trough of 3,665.21, its lowest in 5-1/2 years.European equity indexes slid after Japan's Nikkei <
> fell 6.4 percent to a 26 year closing low while Hong Kong's Hang Seng < > tumbled nearly 13 percent.Miners were among the hardest hit with metal prices falling again. Xtrata <XTA.L>, Lonmin <LMI.L>, Anglo American <AAL.L> and Eurasian Natural Resources <ENRC.L> lost between 7.7 and 10.3 percent.
Colin McLean, managing director at SVM Asset Management in Edinburgh, noted that miners are particularly vulnerable as they are heavily exposed to emerging markets which have seen sharper falls than developed markets in recent weeks.
"Miners are often based in esoteric markets and people are very concerned about what might happen in those countries," he said.
The Group of Seven rich nations tried to cool a rally in the yen with a warning against volatility as Tokyo scrambled to shield its largest banks from a spiralling global financial crisis.
"We're going to get further big swings as the markets watch for what the authorities are going to do," said Neil Parker, market strategist at Royal Bank of Scotland.
UK Prime Minister Gordon Brown has hinted at the possibility that lower inflation thanks to falling oil prices could prompt central banks around the world to make more joint interest rate cuts, the BBC reported. [
]Energy stocks were also on the ropes with U.S. crude oil futures <CLc1> slipping to below $62 a barrel, down from a peak of $147 in July.
BP <BP.L> was down 4 percent, BG Group <BG.L> shed 5.5 percent and Royal Dutch Shell <RDSa.L> lost 5.3 percent.
Banks, which have suffered as the credit crisis has forced the government to nationalise or take large stakes in leading players, were also on the back foot.
HSBC <HSBA.L> shed 8.5 percent while Barclays <BARC.L> lost 2.8 percent and Royal Bank of Scotland <RBS.L> fell 6 percent.
HOUSING WOES
Also weighing on banks, English and Welsh house prices fell by 7.3 percent in the year to October, with the pace of decline accelerating to take prices back to their lowest since March 2006, property consultancy Hometrack said. [
]The banking index <.FTASX8350> is down 11.4 percent this month and mired at its lowest since July 1996.
Insurers were also deep in negative territory with Aviva <AV.L> falling 11.5 percent, the biggest percentage loser in the blue-chip index. The Times said the insurer is reconsidering the terms of a planned 1 billion pound payout to with-profit policyholders. [
]JPMorgan said in a note to clients that dividend cuts within the British insurance sector were likely due to weaker equity markets.
Standard Life <SL.L> fell 6.7 percent while Prudential <PRU.L> lost 3.8 percent.
London Stock Exchange <LSE.L> was down 4.1 percent. The Sunday Telegraph reported the bourse has hired a recruiting firm to find a successor to its long-term chief executive, Clara Furse. [
] (Editing by Quentin Bryar)