Aside from the trade uncertainty, losses among blue-chips were down to Shell, the index's most valuable company, which tumbled more than 4% after warning that uncertain economic conditions could slow its $25 billion share buyback. Homebuilder Crest Nicholson dropped 5.1% on the midcap index after warning that its annual profit could plunge by as much as a third.
Crest highlighted hits from weak consumer confidence and flattening prices as a result of Brexit nerves, and blue-chip housebuilders Persimmon, Barratt and Berkeley each lost about 1%. Lloyds shed 1.4% after missing market expectations for third-quarter arnings. Precious metals miner Fresnillo topped the main board with a near 3% rise, as investors turned to safe haven gold in response to the renewed US-China trade uncertainty.
The FTSE 100 has recorded monthly loss in October, only the third month this year it has done so, as a rally in sterling -mostly driven by the risk of a 'no-deal' exit subsiding - hurt shares in companies that are big exporters. But the mid-cap index marked its second straight month of gains. Gainers among the FTSE 250 were led by specialist media services firm Future Plc which jumped 11.3% to its highest since December 2000 following a proposed acquisition of UK-based print and digital magazine publisher TI Media. Shares in British Airways owner IAG and telecom group BT rose 2.2% and 1.4%, respectively, to outperform the main index after they reported earnings.