LONDON (AP) — Trading on The London Stock Exchange was halted for seven hours yesterday — the bulk of the usual session — angering customers unable to do business on what was expected to have been one of the busiest days of the year.

Traders' woes were further compounded when technical glitches also hit the London platform of the US-based ICE commodities electronic exchange — over-the-counter trading and futures trading were both suspended for around an hour.

The LSE suspended connections to its trading system around 9 a.m. local time after some clients had trouble accessing market data. Trading resumed at 4 p.m. but closed at the usual time just half an hour later.

The shutdown at the LSE, the worst in eight years, proved highly embarrassing for the LSE as it faces growing competition from new European trading platforms.

"Many European clients are furious," said David Buik, an analyst at BGC Partners.

"For the life of me, I cannot understand why the LSE system is not run in duplicate," Buik said, referring to a backup computer system. "So much and so many clients rely on the LSE's durability. They cannot afford to be let down."

The shutdown was especially frustrating given the recent variability in global markets.

"There's been some fury among traders who have wanted to go in," said Justin Urquhart Stewart, a director at Seven Investment Management. "The market has been moving very quickly, and in volatile markets like these you rely on trading systems being there so you can carry out your work."

The shutdown left some clients unable to cash in on a worldwide stock market boom that followed the US government bailout of mortgage giants Fannie Mae and Freddie Mac, which had triggered a 3.8 percent rise in early London trade.

The long break cooled off trading somewhat, with the index creeping up slightly to close up 3.9 percent at 5,446.30.

The shutdown was the biggest disruption to trading since mid-2000, when the LSE was closed for eight hours — also due to a computer fault. In November, the exchange was forced to extend its closing auction after technical problems left traders without live prices for over half an hour.

ICE, which offers futures and contracts for commodities including crude oil, natural gas and electricity, said it did not believe the two incidents were linked.

Buik said the problems could mean the LSE, London's oldest independent exchange, will "lose a larger share of the cake than would be palatable" as rival exchanges come on line.

The London Stock Exchange Group PLC is facing competition from several new platforms, including the investment bank-backed Turquoise, Japanese investment bank Nomura Holding Inc.'s Chi-X, Nasdaq OMX Inc.'s European platform and Plus Market.

Turquoise, which is supported by nine investment banking heavyweights, has said it aims to grab some five percent of the LSE's trading base within months of its launch this month, while Chi-X has taken about 10 percent of the trade in blue chip stocks in recent months.

Nasdaq OMX Europe, which is due to go live later this month, expects to have five percent of the market within a year, and 20 percent in the longer term.

To meet the competition, the LSE announced plans in June to create a pan-European trading facility with brokerage Lehman Brothers to offer a "dark liquidity pool," a trading platform where banks, hedge funds and institutional investors can trade large blocks of shares in secret. It has also recently cut its commission rates.

In a letter published in the Financial Times on Monday, LSE chief executive Clara Furse said that better use of technology had seen the exchange's share of trading in equities exceed 50 percent.

However, she said the LSE was not complacent in the face of competition.

"The emergence of new trading platforms should test the attractiveness of our services," she said.