* 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: Quote, Profile, Research) 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: Quote, Profile, Research) 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: Quote, Profile, Research) on Thursday also helped the market, which now awaits quarterly results from Merrill Lynch MER.N, IBM (IBM.N: Quote, Profile, Research), Microsoft (MSFT.O: Quote, Profile, Research) and Google (GOOG.O: Quote, Profile, Research) for more insight on the global financial crisis.