The FTSE 100 failed to follow Wall Street higher as weakness among utility company and tobacco stocks dragged the blue-chip index lower.
At the close, the FTSE 100 was 0.4% lower at 6,810.
US equities enjoyed some gains as investors looked ahead to trade war talks between the US and China instead of focusing on the ongoing US government shutdown.
The Dow Jones was 0.7% higher at 23,591 by around 4:45pm UK time.
Brent crude oil surged 1.8% to $58 per barrel.
LARGE AND MID CAP RISERS AND FALLERS
Utility Centrica was among the top fallers on the FTSE 100 after the owner of British Gas saw its shares downgraded by Jefferies.
Homewares retailer Dunelm rallied 15.4% to 667.5p after stating that its pre-tax profits would be 'modestly' ahead of market expectations, should the pace of growth seen in the first half continue.
The company did, however, express caution over its full-year outlook, citing unprecedented levels of uncertainty currently facing consumers and businesses in the UK.
Technology and payments specialist Equiniti advanced 2.7% to 200.5p after announcing that it had won a contract from UK communications regulator Ofcom.
Power supplier ContourGlobal was up 2.7% to 189.9p on news it had agreed to acquire two natural gas-fired power plants, and the development rights for a third, in Mexico from Alpek for $724m in cash.
SMALL CAP RISERS AND FALLERS
Consumer goods distributor UP Global Sourcing, known as Ultimate Products, jumped 14.2% to 45p after it announced that it expected its earnings in the 2019 financial year to beat current market expectations.
An upbeat trading update from low-cost housebuilder MJ Gleeson helped the shares rally 11% to 730p.
OptiBiotix Health climbed 4.4% to 94.9p as it entered into an exclusive manufacturing and supply agreement for its weight-management technology in India.
Wealth management and employee benefits company Mattioli Woods was flat at 659p despite forecasting 'strong growth' in first-half adjusted profits, as it also warned of lower-than-expected revenue growth.
Recruitment and training company Staffline firmed 3.3% to £12.50 on news that its PeoplePlus division had won contracts worth £104.6m from the latest round of UK prison education tenders.
Ultrasound software company MedaPhor fell 3.2% to 7.5p as it warned of a deeper full-year earnings loss owing to heavier R&D spending.