The FTSE 100 Index finished a volatile session with a rise of 2.5% as investors battled to digest big moves in oil prices and turmoil in Russia.

The top flight fluctuated throughout the day but a late rebound for oil prices after Brent crude initially dipped to as low as 58 US dollars a barrel ensured the first session of progress in more than a week.

The FTSE 100 Index, which has fallen by more than 8% in December, closed 149.1 points higher 6331.8 amid the turbulent trading.

Brent crude has fallen by about 50% since the summer due to concerns about weakening demand and oversupply.

The slump has been most felt in Russia, where a sudden hike in interest rates from 10.5% to 17% overnight failed to prevent a further decline in the value of the rouble to a record of near 80 against the US dollar.

Sterling looked to be a beneficiary of the switch out of the rouble, together with the euro, with both climbing sharply against the US dollar.

There was some cheer for the UK after inflation fell to a 12-year low in November as lower food and petrol prices kept a lid on the cost of living.

Analysts forecast interest rates may now be on hold for longer but this failed to spook the pound, which was up over 0.5% against the US dollar at 1.57. Sterling was also up against the euro at 1.26.

The late rebound in the price of oil to around 60 US dollars a barrel meant oil services firm Weir rose more than 4%, or 72p at 1782p, while Tullow Oil lifted 22.6p to 381.4p and Royal Dutch Shell added 105p at 2094p.

Investors in the banking sector were relieved by the outcome of the Bank of England's latest stress tests, with only the unquoted Co-operative Bank in need of resubmitting its capital plans.

Barclays was 2% or 4.95p higher at 230.15p and HSBC was up 11.3p to 603.5p.

Royal Bank of Scotland lifted 8.3p to 372p, even after it said it would issue £2 billion worth of convertible bonds in the wake of the stress test.

Lloyds Banking Group was up 2.5p at 76.9p amid continued uncertainty over whether its result will mean it can restart dividend payments next year.

Elsewhere, Sainsbury's slipped 0.1p to 229.4p after industry data showed that its sales fell 1.8% and its market share dropped to 16.5% from 16.8% in the 12 weeks to December 7.

The biggest risers in the FTSE 100 Index were Tullow Oil up 22.6p at 381.4p, Capita up 63p at 1065p, Intertek up 121p at 2270p and Royal Dutch Shell up 105p at 2094p.

The biggest fallers in the FTSE 100 Index were Randgold Resources down 54p at 4040p, Fresnillo down 7.5p at 704.5p, Coca-Cola HBC down 11p at 1221p and Burberry down 4 at 1590p.

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