(Reuters) Britain's top share index rose sharply on Wednesday reversing earlier session losses after China cut its banks' reserve requirement ratios and central banks announced coordinated global action to provide liquidity to the financial system.

Gains were extended around midday after the central banks of the United States, euro zone, Japan, Canada, Britain and Switzerland announced the coordinated global action.

Investor sentiment improved after China's central bank cut the reserve requirement ratio for its banks by 50-basis-points, in the first time in nearly three years, in a move which will help ease a slowdown in the world's second largest economy.

The FTSE mining sector, whose performance is highly correlated to global growth, turned positive after the surprise China cut and the sector which was initially in the bottom performers list rebounded to near the top.

Miners which have exposure to China, Kazakhmys and Antofagasta, were amongst the main movers and were up 6.6 percent and 8.4 percent respectively.

It is really significant as China is looked to for economic leadership, said Mike Lenhoff, chief strategist at Brewin Dolphin.

This is a confirmation of reversal of policy and China can help provide stability to the global economy at a time where stability is being put at risk because of the sovereign debt crisis.

Banks were also helped by the positive sentiment after the China cut and turned higher, lifting them out of the bottom performers list.

Earlier, the sector had featured among the worst performers after a Standard & Poor's downgrade of 15 big banks including HSBC and Barclays sparked worries about higher funding costs.

But the push higher by banks was not yet enough to get the sector out of the red for November and the bank index is on track to end the month 8.8 percent lower as worries about the euro zone sovereign debt crisis hit sentiment as other countries like Italy become engulfed.

The euro zone crisis appears to be moving towards full-blown contagion with stresses now evident across the sovereign bond market in Europe, UBS said in a note.

The UK's FTSE 100 was up 153.19 points, or 2.9 percent at 5,492.73 by 1308 GMT on the last trading day of the month, having been as low as 5,274.95 and is on track to end November down 1 percent.

The index jumped above its 38.2 Fibonacci Retracement at 5,382.02 points from its August low to October high, with the next resistance level seen at the 23.6 Fibonacci Retracement at 5,521.64.