Falls by energy stocks and financials, unsettled by persistent market jitters, outweighed gains from defensive drugmakers and tobacco stocks to push Britain's top share index slightly lower by midday on Monday.
By 1220 GMT, the FTSE 100 index was 10.20 points lower at 5,050.70, retreating from strong gains earlier in the session after closing 78.39 points, or 1.5 percent, lower on Friday.
Banks turned negative as early optimism that euro zone debt problems might be receding evaporated.
Barclays, HSBC, Standard Chartered, Royal Bank of Scotland and Lloyds Banking Group fell 0.1-2.8 percent.
European finance ministers tried to assure their counterparts in the G7 that the eurozone's debt crisis is under control. They said they would make sure that Greece sticks with its budget cutting plans.
"There is caution on the outlook for corporate profits, sovereign debt markets and the economic outlook, so there are a variety of crosscurrents to contend with… it will continue to be volatile," said Neil Veitch, fund manager at Scottish Value Management in Edinburgh.
Insurers were also weak as confidence in the financial system was shaky once again.
Legal & General, Aviva and Prudential fell 3-4 percent.
The mining sector, which suffered last week as metal prices retreated, was supported by reassuring results from Randgold Resources.
Randgold was the top FTSE 100 riser, up 5.4 percent. The gold miner said its full-year profit jumped 79 percent and it brought forward the expected start-up of production from the Kibali project to January 2014.
But other miners retreated from early gains with a fresh darkening of the demand outlook.
The main support for the blue chip index were defensive plays like pharmaceuticals and tobacco stocks which tend to outperform when risk appetite fades.
AstraZeneca, GlaxoSmithKline and Shire added 0.5-1.2 percent, while Imperial Tobacco and British American Tobacco gained 0.9 and 1.5 percent respectively.
ENERGY DRAIN
Energy stocks acted as a big drag on the index as crude gave up some of its early gains. BP, Royal Dutch Shell and Tullow Oil fell 0.4 to 1.3 percent.
BG Group's rating was cut to "equal-weight" by Barclays Capital following results on Friday and its shares lost 3 percent while Cairn Energy shed 4.5 percent.
Among other blue chip fallers, chip designer ARM Holdings fell 2.7 percent on its FTSE 100 debut, having replaced Cadbury at the close on Friday.
Among individual blue chip gainers, International Power added 2.2 percent after a report in the Independent on Sunday said France's GDF Suez is mulling a revised offer for the British power generator, including a cash element.
ICAP recovered 2.7 percent after Friday's plunge which was sparked by a profit warning, helped by a Credit Suisse upgrade to "outperform", with the broker calling the falls "overdone".
Wednesday's Bank of England Inflation Report will be the week's main focus in terms of UK economic data this week, with nothing significant scheduled for release on Monday.
