All but one of the blue-chip index's sectors were in red as it shed 0.4% in early deals. The mid-cap FTSE 250 lost 0.2% by 0709 GMT.

Slug and Lettuce owner Stonegate Pub Company <IPO-SPC.L> agreed to buy Ei Group for 285 pence a share, a 38% premium to Wednesday's close that sent the mid-cap pub chain's stock to its highest in more than a decade.

AIM-listed online fashion retailer ASOS tanked almost 20%, as it blamed operational issues for its third profit warning in eight months.