Prime Minister Theresa May's announcement that she will seek 'maximum possible access' to the single market and allow MPs to scrutinise the plan to leave the EU caused the pound to rally against the euro and dollar.
The FTSE 100 slumped 0.6% to 7,024 as investors awaited the minutes from the latest US Federal Reserve meeting on interest rates. Wall Street opened lower as investors were cautious over higher US bond yields.
West Texas Intermediate (WTI) crude oil slid 1.3% to $50 and Brent crude fell 1.1% to $51.84 per barrel, respectively.
Gold was flat at $1,253 per ounce and copper rose 0.2% to $4,806 per tonne.
MAIN NEWS OF THE DAY
Mining giant Fresnillo (FRES) remained on track to deliver its full-year production guidance, after reporting quarterly results in line with expectations. It was flat after the firm said the second phase of commissioning of the San Julian mine was pushed back.
MID CAP RISERS AND FALLERS
Scandal-hit sports retailer Sports Direct (SPD) declined 4.7% to 279.7.5p after Cantor Fitzgerald downgraded profit estimates following losses on exchange hedging contracts.
Pizza delivery chain Domino's Pizza (DOM) failed to impress the market after reporting sales growth in the third quarter of 2016, driven by new stores, and remained upbeat on meeting full year market expectations.
Construction firm Kier (KIE) sold its Mouchel Consulting business to WSP Global for £75m, which will be used for future investment and to cut debt.
SMALL CAP RISERS AND FALLERS
Shares in Premier Foods (PFD) declined 6.3% to 48.93p after warning that first-half profit was likely to be below the previous year and posted a drop in second quarter sales due to warmer weather.
Mining minnow Strategic Minerals (SML) continued to soar 23.5% to 1p despite management confirming there was no new news to report a few days ago. The stock rallied 160% in six trading days.
Strong trading and an improvement in cash collection at digital TV solutions supplier Mirada (MIRA) caused the shares to gain 18.5% to 4p.
Oil and gas production company Petroneft Resources (PTR) jumped 13.8% to 3.3p as gross barrels of oil per day rose from 2,460 in the second quarter of 2016 to 3,317 in the third quarter.
Diamondcorp (DCP) cheapened 33.3% to 2.75p on reports of drilling problems at its Lace diamond mine in South Africa, leading the firm to ask investors for a further cash injection of between £2.5m and £3m.
Biotech Synairgen (SNG) crashed 32.3% to 23p on reports that its partner AstraZeneca (AZN) called time on INEXAS asthma treatment after the latest clinical trials data.