By Ambar Warrick and Sagarika Jaisinghani
(Reuters) - The British blue-chip index ended down on Monday with energy stocks tracking a decline in oil prices, while AstraZeneca marked its strongest close ever on optimism over its COVID-19 vaccine.
The commodity-heavy FTSE 100 index <.FTSE> was down 0.5% on the day, with BP Plc <BP.L> and Royal Dutch Shell Plc <RDSa.L> among the biggest drags as oil prices fell in anticipation of weaker demand.
Heavyweight drugmaker AstraZeneca <AZN.L> helped cap some losses, rising 1.5% after data showed its experimental COVID-19 vaccine was safe and produced an immune response in early-stage clinical trials in healthy volunteers.
Still, the stock ended largely off an intra-day record high hit in anticipation of its announcement.
The mid-cap FTSE 250 <.FTMC> closed 0.2% higher, propped up by Future PLC <FUTR.L>. The media firm surged more than 15% after it forecast annual performance to be at the top end of market expectations.
"Following the (steep rise) from March lows, markets need another dose of positive news to keep the rally going, but given the many uncertainties ahead, the risks seem tilted to the downside," said Hussein Sayed, market strategist at FXTM.
The FTSE 100 has bounced about 27% following a coronavirus-driven crash in March, but the pace of gains has slowed since June amid fears of a slower-than-expected global economic recovery.
A recent survey showed that nearly half of Britain's biggest companies think they will take until the second half of 2021 before businesses recover from the pandemic.
Among individual movers for the day, Marks and Spencer <MKS.L>, one of Britain's best known high-street names, fell slightly on a report that it planned to announce hundreds of job cuts in the coming week.
BHP Group <BHPB.L>, the world's largest miner by market capitalization, ended flat ahead of its quarterly production results.
Homebuilders <.FTNMX3720> gained about 0.8% as a report said a mini housing market boom was gathering pace after a tax cut by finance minister Rishi Sunak.
(Reporting by Sagarika Jaisinghani in Bengaluru; Editing by Patrick Graham and Sherry Jacob-Phillips)