Britain's leading share index closed 2.5 percent lower on Thursday, with market sentiment hit by data showing U.S. employers cut more jobs than expected in June and unemployment in Europe hit a 10-year high.

The FTSE 100 index ended down 106.44 points at 4,234.27 after closing 2.2 percent higher on Wednesday, the first day of the new quarter.

Data showed the world's biggest economy lost 467,000 jobs in June, 100,000 more than expected by economists and breaking a four-month trend of slowing U.S. job losses.

"This proves that we may not be at the bottom yet. The world's biggest economy, as we know them, is going to be dragged down," said Philip Gillette, a sales trader at IG Index.

The energy sector, which gained in the previous session on higher oil prices, took the most points off the index as crude fell more than $2 to trade below $67 a barrel.

BP, Royal Dutch Shell, BG Group and Tullow Oil fell 1.9-3.3 percent.

"Sentiment has changed over the last two or three weeks, from being very bullish to people realising the fundamentals are not that rosy," said Gillette.

Lower metal prices helped push miners down, shedding some of the recent gains. Randgold Resources, Eurasian Natural Resources , Anglo American, Lonmin and BHP Billiton fell 3.1-4.7 percent.

Rio Tinto fell 5.7 percent. It completed the British leg of its $15.2 billion rights offer, putting the world's top iron ore miner back into growth mode after slashing its debt.

UNEMPLOYMENT RISES

British data showed a decline in activity in the construction sector accelerated in June, and lenders said they did not expect much of a pick-up in demand in the third quarter.

Data showing the jobless rate in the 16-nation euro zone rose to 9.5 percent in May, the highest since 1999, also weighed on the FTSE.

"I certainly think unemployment will continue to rise over the next few months and maybe into next year, and this will bring its own negative impact on aggregate demand," said Jeremy Batstone-Carr, analyst at Charles Stanley.

The fall in equity prices was broad-based, with defensive drugmakers and banks also among those into negative territory.

AstraZeneca, GlaxoSmithKline and Shire fell 2.4-2.8 percent.

Heavyweight HSBC was 1.8 percent lower, while Lloyds Banking Group, Royal Bank of Scotland and Standard Chartered fell 2.1-3.4 percent.

WPP Group slipped 7 percent, the biggest loser on the index, as Citigroup downgraded the advertising group's rating to "sell" from "neutral" with a reduced target price of 340 pence, down from 440 pence.

With most stocks down on the day, the world's biggest spirits group Diageo topped the risers chart, up 0.9 percent, as traders continued to view its decision, announced on Wednesday, to close two Scottish plants as a good move in the current downturn.