UK's FTSE 100 inched lower on Wednesday on mounting concerns over the impact of the Omicron coronavirus variant on economic recovery and weaker-than-expected quarterly growth data.

The blue-chip FTSE 100 index fell 0.2%, while the domestically focussed mid-cap index was flat by 0810 GMT.

Miners fell 0.8%, with Rio Tinto Plc leading the fall as benchmark Dalian and Singapore iron ore futures fell amid concerns over COVID-19 curbs in China.

Data showed Britain's economy grew slower than expected in the July-September period, before the Omicron variant posed a threat to economic recovery.

Prime Minister Boris Johnson said on Tuesday that he would not be introducing new COVID-19 restrictions in England before Christmas.

Rolls Royce gained 1.1% on plans to invest in methanol technology for climate-friendly shipping.