(Noon): The London market rose 1% as investors reacted to the latest comments from the US Federal Reserve.
(Close): London's benchmark index rose 2% as investors welcomed news that UK retail sales had risen at their fastest annual rate in more than 10 years.
The Fed said it would take a "patient" approach to raising interest rates, adding that there would be no move for "at least a couple of meetings".
Additionally, news that US central bank would take a "patient" approach to raising interest rates buoyed international markets.
This implies there will be no rate rise before April, but analysts still expect the Fed to act by mid-2015.
The FTSE 100 closed up 129.52 points, or 2%, at 6,466.
The FTSE 100 was up 61.66 points, or 1%, at 6,398.14. Energy shares were up as oil prices strengthened.
Financial services firms Old Mutual and Aberdeen Asset Management both rose by more than 5%.
Having fallen as low as $58.50 earlier in the week, Brent crude rose above $63 a barrel following signs that oil producers are scaling back investment because of the recent slump in prices.
Brewer SABMiller added 5.6%, while British tech firm ARM Holdings added 4.9%.
Among oil-related stocks, Petrofac shares rose 5.6%, Tullow Oil was up 2.2% and BP was nearly 1% higher.
British Airways owner IAG ended the day 4.5% higher, after revealing that the Irish carrier Aer Lingus had rejected its takeover offer.
Shares in chip designer Arm Holdings rose 3.6% after brokerage Exane cited upbeat comments from the company about prospects for the Chinese smartphone market.
Aer Lingus shares, meanwhile, were almost 9% higher.
On the currency markets, sterling was boosted by strong UK retail sales figures, which were helped by the impact of Black Friday promotions.
The pound was up 0.6% against the dollar at $1.5662 and rose by 1% against the euro to €1.2742.
The pound was up 0.5% against the dollar at $1.5657 and rose more than a cent against the euro to €1.2720.
