The blue-chip FTSE 100 index dropped 1.1%, with oil stocks, miners and financials among the worst performers.
BP and Royal Dutch Shell shed 1.7% and 1.0%, respectively, tracking oil prices lower.
Online electricals retailer AO World fell 11.3% after reporting that its revenue in the first half was hit by a shortage of delivery drivers in the UK and other disruptions to the global supply chain.
The domestically focussed mid-cap index declined 1.2% on weakness in travel and leisure shares.
Pub operator Wetherspoon dropped 4.7% after reporting a near doubling of its annual losses as sales were hit by COVID-19 restrictions.