The FTSE 100 was down 0.7% by midday amid global growth fears, despite some grounds for optimism in a key survey on German business sentiment.
US futures are pointing to modest losses on Wall Street later, following the big sell off on Friday.
LARGE AND MID CAP RISERS AND FALLERS
Sports Direct fell 0.5% to 284.2p on confirming that it had made a takeover bid to struggling retailer Debenhams for its Danish department store chain Magasin Du Nord. Debenhams ticked up 1.3% to 1.61p
Contractor company Wood Group dropped 7.9% after it announced that it had sold its non-core Terra Nova Technologies business to a Murray & Roberts Holdings unit for $38m.
Inmarsat soared 8.6% after accepting a takeover bid by a consortium led by private equity groups Apax and Warburg Pincus in a deal that valued the satellite company at $3.4bn.
Subprime lender Provident Financial declined 1.6% to 514.4p as it announced the appointment of a new chief executive and chairman to its Vanquis Bank unit, while reiterating its rejection of a takeover bid from Non-Standard Financial.
Medical products supplier Convatec gained 4.6% to 140.5p after it poached Genus head Karim Bitar as its new chief executive.
SMALL CAP RISERS AND FALLERS
Wine retailer Majestic Wine slid 11.8% to 239p on revealing that it was reviewing its dividend amid a plan to invest more capital in its Naked Wines online business unit.
Banknote and product authentication technology group Spectra Systems shed 4% despite it posting a 30% rise in annual profit.
Ovoca Bio jumped 19% on news that it had recorded positive results from a trail of a treatment for hypoactive sexual desire disorder in premenopausal women.
Textile processor Leeds Group fell 2.1% after it warned on profits, citing increased competition in a weaker market.