Equities slid as the shadow of Sunday’s Greek referendum on the eurozone bailout depressed investor sentiment.
Greek prime minister Alexis Tsipras has urged the country to vote against austerity proposals – with financial markets worried about contagion if the country leaves the single currency launched in 1999.
The FTSE 100 index closed down 44.69 points at 6,585.78, and has fallen 168 points over the week as the issue has continued to unnerve investors.
Trustnet Direct analyst Tony Cross said: “Regardless of the outcome, a degree of volatility on Monday morning seems inevitable – there’s no clean outcome for this.
“The expectation is that a verdict from Greece may well be released late on Sunday night - what happens beyond that, however, is another step into the unknown.”
That uncertainty outweighed positive economic news from Britain’s dominant services sector, which grew more than expected last month.
Even though the sector accounts for 75 per cent of British GDP the news did also not greatly impact the pound, which was flat against the dollar at $1.56.
Sterling was also broadly unchanged against the European currency, trading at €1.40. “The betting is that any rise in UK interest rates is still quite some way off,” one dealer said.
Heavyweight miners were down on news that iron ore prices have slipped 5 per cent. BHP Billiton was 24p lower at 1,248.5p, Anglo American fell 15.8p to 902.4p and Glencore was down 3.1p to 252.7p.
Royal Bank of Scotland was 6.8p down to 359.3p after reports that the bank could face a $13 billion (£8.3bn) fine from US regulators over claims that it misled investors in mortgage-backed securities.
Other banks were also in negative territory, with Barclays 3.5p lower at 263p, HSBC down 5.1p to 572.9p and Lloyds Banking Group slipping 1.1p to 85.1p.
Elsewere, BP gave up further early gains, following on from a 4 per cent lift on Thursday when the oil major revealed that it had reached a $18.7bn (£12bn) legal settlement in the US to cover the Deepwater Horizon explosion and oil spill five years ago. The shares later closed down 3p at 434.4p.