Vodafone was among the fallers in the London top flight amid rumours that it was considering deals large and small.
On the one hand, there has been speculation that the mobile network provider is weighing up a potential combination with Virgin Media owner Liberty Global.
On the other hand, Vodafone was said to have held talks on buying loss-making video streaming service Blinkbox from Tesco.
Either way, shares in the mobile phone firm were down 6.75p at 227.2p, as the wider FTSE 100 slipped 66.25 points to 6,656.37.
Jasper Lawler, market analyst at CMC, said: “Blinkbox was always an odd fit for a supermarket but a mobile phone network may not be much better. It’s debatable how much of a pull it’ll be for Vodafone customers who already have access to iTunes, Google Play, Sky TV, Netflix and a host of other movie-streaming services through native apps on their phones.”
Meanwhile, crude prices continued to drift lower and manufacturing surveys from around the world did little to shore up commodities. Although Britain’s industrial purchasing managers’ index beat expectations, China’s didn’t, while Europe was a mixed bag.
Tullow Oil was the biggest faller, down 6 per cent at 400.5p as a number of brokers downgraded the stock in light of the slump in oil prices.
Outside the top flight, Irish oil group Petroceltic, which bought Edinburgh’s Melrose Resources two years ago, saw its shares slump more than a third after suitor Dragon Oil ruled out a takeover, citing the fact that a barrel of oil has fallen around 35 per cent since the deal was announced in October. Petroceltic stock lost 60.5p at 113.5p, but Dragon was one of the few drillers in the black, adding 1.5p to 502p.