The FTSE 100 ended the week on a lacklustre note, slipping back to around the 7,500 level with earlier gains wiped out in afternoon trading.
Housebuilders and insurers were in vogue while utilities and drug companies struggled on the blue chip index.
US markets fared better, with the S&P 500 up 0.1% to 3,003 and the Dow Jones up 0.5% to 27,209 at 4.20pm UK time.
The main corporate news was a 61% slump in Thomas Cook's share price after the struggling travel company revealed it was in advanced discussions with largest shareholder Fosun and its core lending banks about a potential £750m recapitalisation and break-up of the group.
The move, which would see Fosun take a majority stake in Thomas Cook's tour operator business and a minority stake in its airline, would result in existing shareholders being 'significantly diluted'.
Thomas Cook also warned that it would post a fall in second-half operating earnings.
LARGE AND MID CAP RISERS AND FALLERS
Advertising company WPP added 0.5% on announcing that it had agreed to sell 60% of its data and analytics unit Kantar to Bain Capital in a deal that valued the business at around $4bn including debt.
Proceeds to WPP on completion after tax and continuing investment in Kantar were expected to be around $3.1bn (£2.5bn), of which around $1.2bn (£1.0bn) would be returned to shareholders.
Insurance company Hiscox fell 2.2% after it downgraded its profit guidance following a string of bad weather events, including a typhoon in Japan and a hurricane in Florida.
Asset manager Ashmore reversed 0.9%, despite boosting its assets under management by 7.5% in the second quarter. Net inflows amounted to $3.3m, though the company experienced a small net outflow from its equities funds.
Car retailer Lookers tumbled 9% as it warned that its profits would take a hit this year, amid falling consumer demand for cars and rising costs. Fellow dealership Pendragon was down 6.3% in sympathy.
Cyber-security expert Sophos gained 4.3% on announcing that its revenue had grown by 3% in the first quarter, as growth in subscription sales offset a fall in hardware sales.
SMALL CAP RISERS AND FALLERS
Aviation services group John Menzies shed 0.5% after announcing that chairman Dermot F Smurfit had stood down with immediate effect. He had been replaced by current non-executive director Philipp Joeinig.
Fund manager Miton Group fell 2.3%, despite posting an 8% rise in first-half assets under management. The rise was due to market performance, which offset £82m of net outflows from the company's funds.
Fitness centre chain The Gym Group rose 3.1% after it said its revenue had jumped 27% in its first half.
Science Group added 2% as it increased its holding in takeover target Frontier Smart Technologies Group to 35.8%. Frontier's shares fell 2.8%.