The FTSE 100 has ended up 103.90 points, or 1.99%, to 5317.30 after reports of a number of takeover bids sent stocks of O2 soaring.
The FTSE 100 has made a strong start to the day with a rise of 67.40 points, or 1.29%, to 5280.80, led higher by gains for O2 and P&O after both companies received takeover approaches.
After a topsy-turvy day the FTSE has ended on a high moving up 30.60 points, or 0.59% to close at 5213.40 after reports of good GDP growth in the US gave a last minute boost to the index.
The FTSE 100 has erased about half its gains from yesterday currently down 20.1 points to 5207.7 despite good earnings reports from Shell and British American Tobacco.
After an early afternoon lull, the FTSE 100 has ended up 45.7 points, or 0.88%, to 5227.80 at its close, with oil and mining stocks topping the risers.
A solid performance from oil and mining stocks and a big advance from SCi entertainment has pushed the FTSE 100 through the 5,200 mark leaving it up 65.50 points, or 1.27%, to 5,207.60 at the end of trading.
After a bright start the FTSE 100 sliding into an eventual loss of 3.70 points, 0.07%, to 5164.10, after spending the day in uncertainty as tumbling crude oil prices hit the energy sector.
The FTSE 100 has rebounded strongly, moving up 47.8 points, or 0.92%, so far to 5,215.60 after its sharp fall yesterday.
In the UK the FTSE 100 Index has added 5.2 points, or 0.1% to 5291.7 at its opening as stocks, including Rio Tinto, rose as commodity prices climbed.
In the UK FTSE 100 Index rose 11.5 points, or 0.2%, to close at 5286.5 although airlines including British Airways limited the advance as higher oil prices threatened to erode earnings