Shares in Primark owner Associated British Foods surged after it unveiled plans to launch the budget fashion chain in the US at the same time as it also published more strong trading figures from Europe.
The FTSE 100-listed conglomerate, whose operations cover sugar, agriculture, retail, grocery and ingredients, was the stand-out performer with a 9% rise during an otherwise lacklustre session for the London market.
The top-flight was 7 points lower at 6674.7 as weak manufacturing data in China proved a major obstacle to further gains after the euphoria at the start of the week over a flurry of major deals in the pharmaceuticals sector that helped add 56 points.
Blue-chip shares slid downwards despite more encouraging signs from the eurozone after a key measure of business activity rose to its highest level in three years. Worse-than-expected home sales data from the US helped dampen sentiment, with Germany's Dax and France's Cac 40 both sliding and New York's Dow Jones Industrial Average also in the red at the time of the close in London.
On currency markets, sterling lost ground after minutes from the latest meeting Bank of England's rate-setting committee expressed uncertainty about the level of slack in the economy.
The pound fell a cent against the greenback to 1.68 US dollars and was at 1.21 euros.
AB Foods delivered the biggest blue-chip rise of the session after Primark's plans for a store in Boston by the end of next year were accompanied by a 26% rise in retail profits. Shares were 240p higher at 2962p as AB Foods also reported a 4% rise in group profits to £468 million.
Elsewhere, drugs stocks continued to improve on the back of deal-making activity by GlaxoSmithKline and speculation linking AstraZeneca to a potential takeover by US giant Pfizer.
Glaxo rose 2.5p to 1642.5p and Astra added 2%, or 82.5p to 4042.5p, having risen by 5% in the previous session.
In the FTSE 250 Index, holiday company Thomas Cook rose 4.4p to 178p after its turnaround strategy was backed in a broker upgrade from Barclays, whose analysts expect a resumption of dividend payments in 2016.
Top flight rival TUI Travel also rose, by 1.2p, to 427.9p.
The biggest decline in the FTSE 250 Index came from power station business Drax after it was offered an investment contract from the government to convert just one of its two coal-fired generators to biomass fuel.
Drax shares slumped 13% or 99p to 657.5p.
The biggest FTSE 100 risers were Associated British Foods, up 240p to 2962p, Admiral up 45p to 1408p, Bunzl up 38p to 1654p and AstraZeneca up 82.5p to 4042.5p.
The biggest FTSE 100 fallers were Antofagasta down 48p to 796.5p, Centrica down 14.3 to 330.6p, Hargreaves Lansdown off 50p at 1197p and Sports Direct down 33p to 797p.