Drugs firm AstraZeneca was the top riser on the FTSE 100 amid talk that US rival Pfizer was planning to make another approach.
Earlier this year Pfizer sent shares in the sector soaring when it staged a failed £69 billion takeover attempt on Astra.
It came as Astra announced that it had signed a deal with gene sequencing company Illumina to develop a platform for tests for its cancer drugs.
Analysts at Beaufort Securities said: “The company, as a whole, has been making multiple strategic acquisitions lately, adding critical drugs with attractive commercial potential into its portfolio.”
Shares rose 3 per cent, or 126.5p, to 4,411.5p. The FTSE 100 Index climbed 22.18 points to 6777.66 as data showing a slowdown in retail sales further weighed against an early rise in interest rates.
With food spending seeing its first year-on-year decline on record, Tesco was down 1.4p at 245.5p. Sainsbury’s was almost flat at 307.1p but Morrisons advanced 1.5p at 176.3p.
The outlook on interest rates helped builder Barratt, which saw shares add 6.6p to 366.2p. Fund managers also benefitted, with Schroders and Hargreaves Lansdown both advancing more than 2 per cent to 2,392p and 1,133p respectively.
In the FTSE 250, retailer WH Smith was in focus after it said full-year results to the end of August were likely to be in line with market expectations. Shares rose 15p to 1,137p.
Meanwhile engineering contractor Costain experienced a choppy session after announcing a record order book thanks to its securing work on a series of major infrastructure projects.
It also ramped up its interim dividend by a third. But after an initial climb, the stock headed 3.2p lower to 269.8p.