A gain of almost 2 per cent marked the best single day performance for the index in more than a year – it was up 114.38 points at 6,310.29 – leaving analysts unsure as to which way the trends are now pointing.
Tony Cross market analyst at Trustnet Direct, said: “The better than expected US economic data we’ve seen has helped cement gains, whilst the fact the Bank of England is once again talking down prospects of a rate hike is also adding a degree of support, but it’s difficult not to just see a lot of the move as being bargain hunting as investors move back in.”
Oil prices also picked up, with Brent crude heading above $86 a barrel after dropping to a four-year low of around $83 in the previous session.
That helped heavyweight Royal Dutch Shell lift 80.5p to 2,240.5p and BP improve by 8.5p to 428.5p.
Exploration and production group Tullow Oil was the biggest climber on the top flight, adding 8 per cent or 40.1p, to 524p after a broker upgrade from Societe Generale.
Oilfield service company Petrofac was just behind with a rise of 7 per cent, or 72.5p, to 1,060p. It came after the group said backlogs had improved and confirmed it was on track to hit profit targets.
Rolls-Royce was the leading faller as the deteriorating economic conditions behind the recent slump in stock markets were blamed by the engines giant for a downgrade to its sales and profits guidance in 2015.
The company had already ruled out growth this year due to defence spending cuts but now expects that profits in 2015 will be up to 3 per cent lower. Shares fell nearly 12 per cent, or 108.5p, to close at 832p.