Banks, oil shares power FTSE's 2.2 percent jump

* FTSE 100 jumps 2.2 pct.

* Banks top gainers, driven by U.S. banks' results

* Oils, mining stocks rise on broader market tally

By Atul Prakash

LONDON, July 17 (Reuters) - Britain's blue-chip index rose 2.2 percent at midday on Thursday, as banking shares spiked after results from JPMorgan (JPM.N) eased worries about a credit crisis, and weaker crude prices lowered inflation concerns.

By 1117 GMT, the commodity-heavy FTSE 100 .FTSE was up 113.9 points at 5,264.5, after closing down 0.4 percent on Wednesday, when it hit a three-year low.

Banks were in demand, with the sector topping the UK benchmark index, after unexpectedly strong results from Wells Fargo (WFC.N) lifted the U.S. stock market over 2 percent on Wednesday -- the best day for banks in 16 years.

Better-than-expected results from JP Morgan (JPM.N) on Thursday also helped the market, which now awaits quarterly results from Merrill Lynch MER.N, IBM (IBM.N), Microsoft (MSFT.O) and Google (GOOG.O) for more insight on the global financial crisis.