The FTSE 100 passed the 6,900 barrier for the first time in 14 years but was dragged back by BP after a US court opened up the possibility of more Gulf of Mexico related fines.
The index closed just 4.39 points higher at 6,877.97 as traders struggled to get to grips with the latest stimulus package from the European Central Bank.
Alastair McCaig, market analyst at IG, said: “Any chance the FTSE had of closing above the 6,900 level have this afternoon been dealt a blow as BP shares instantly dropped following the news that US courts have found them to be ‘grossly negligent’ in their Deepwater Horizon operations.”
BP’s shares slumped almost 6 per cent, down 28.75p to 455p, and counteracted the positive effect from Standard Life.
The Edinburgh-based investments group was the biggest riser in the top flight after saying it would return £1.75 billion to investors following the sale of its Canadian business. Shares closed 8.1 per cent higher, up 31.1p to 417.2p.
Stocks making progress on the FTSE 250 included transport operator Go-Ahead, after it posted a 44 per cent increase in profits. Shares climbed 72p to 2,345p as the company announced the first hike in its full-year dividend in six years.
Also on the up was SuperGroup, the firm behind the Superdry fashion brand, after its trading figures for its financial first quarter showed revenues up 15.9 per cent to £87 million. Its stock lifted almost 14 per cent, or 145p, to 1,191p.
Shares in newspaper group Johnston Press were lower despite the announcement that all six of its non-executive directors had added to their stakes in the company. The shares traded 1.7 per cent lower at 3.86p, although the board members had paid 4.1p a share for theirs.