The biggest FTSE 100 faller was oilfield services company Petrofac, which lost nearly a quarter of its value after issuing a profits warning.
It said it expected net profit for 2015 of $500million (£320million), due to lower oil prices and expectations for the delivery of some projects, with current oil price expectations expected to result in a $45million (£29million) hit.
The figure will be a fall on the expected net profit this year at the lower end of a $580million to $600million (£371million – £384million) range. Shares fell 24%, or 285.8p, to 907.2p.
Elsewhere, Friends Life shot to the top of the FTSE 100 risers’ board today with a 7% climb after the disclosure that it was involved in advance merger talks with Aviva.
Shares rose 25p to 372.7p with the all-share offer valuing Friends Life at 398.9p, a 15% premium to its value at the close last Friday – while Aviva dipped 4%, or 20.2p, to 518.8p.
The wider FTSE 100 Index was flat, ahead by just 5.5 points to 6756.3.
Investors were still digesting the announcement of the proposed Aviva deal, announced after the close at the end of last week, putting a £5.5billion value on Friends Life – which said it would recommend the terms to shareholders.
Tony Cross, market analyst at Trustnet Direct, said: “The target appears to be willing to roll over already suggesting that the offer is a shade too generous and Aviva has seen its shares fall back as a result, whilst Friends Life is very much in favour.”