But consumer goods giant Reckitt jumped after a forecast-beating sales rise.

The FTSE 100 index was down 0.2 percent by 0935 GMT, lagging its European and Asian peers, while the midcap bourse gained 0.4 percent lifted by the pound.

Sterling rose as investors waited for the outcome of Brexit talks between Britain and the European Union, while the dollar took a hit as investors eyed risky assets on China-US trade optimism.

Defensive stocks, which are deemed to be a safe bet at times of uncertainties, were among the big fallers in early deals. Healthcare and consumer stocks led the fall with Accendo Markets analyst Michael van Dulken pointing to some profit-taking.

"I guess many people have been looking with the FTSE in a rising channel and nudging the ceiling of the channel, 'let's crystallise some of those profits before they get pulled away either by a trouble with trade talks or a Brexit problem'," van Dulken said.

As a result, oil majors BP and Shell inched lower despite higher crude prices.

Reckitt Benckiser was a ray of sunshine, rising 4.5 percent on track for its best day since late-July as its fourth-quarter sales growth topped estimates.

Another notable blue-chip faller was BAE Systems with a 1.2 pct dip after an Airbus official said Germany's halt in exports to Saudi Arabia was preventing Britain from completing the sale of 48 Eurofighter Typhoon warplanes to Riyadh.

On the small cap index, convenience retailer McColl's shares jumped 10.7 percent after saying it was on course for higher like-for-like sales in the first quarter and Petra Diamonds added 8.4 percent after naming a new CEO.

Mid-cap online trading platform Plus500 fell 4.4 percent after it confirmed late on Friday that it failed to disclose certain losses from customer trading due to a drafting error in its 2017 report.

Plus500 lost nearly half its value last week after a profit warning and a Times newspaper report of the accounting lag.

AIM-listed Footasylum more than doubled in market value and was on course for its best day ever after JD Sports bought an 8.3 percent stake and said it was prepared to increase its holding up to 29.9 percent.

"The macro risk looks like it's been incorporated in forecasts more than it has for a while.

If we do get a (Brexit) delay and an agreement there's a bit of potential upside," said Ian Williams, strategist at Peel Hunt.