By Kit Rees and Alistair Smout
LONDON (Reuters) - Britain's top share index rallied for a fourth straight session on Wednesday as appetite for under performers in the mining sector continued to build, led by a surge in miner Glencore .
The FTSE 100 <.FTSE> was up 2.4 percent at 6,000.01 points by 1513 GMT, taking gains over the last four sessions to more than 8 percent.
Commodities and mining firm Glencore jumped more than 15 percent, touching its highest level since November, although the volatile stock has lost around two-thirds of its value since May.
Traders said the firm's early refinancing of some of its debt was supporting the stock. The debt had been under close watch as falling commodity prices put a strain on balance sheets.
"One of the main reasons for the relative underperformance in the mining sector and Glencore was due to high debt levels and risks of more credit downgrades," Atif Latif, director at Guardian Stockbrokers, said.
"We are pleased to see this news allowing some de-risking on the share price as balance sheet concerns have eased."
Anglo American rose more than 10 percent, extending a rise from the previous session, which saw the stock finish 1.3 percent higher following volatile trade in the stock in light of its results.
Deutsche Bank raised its target price on the stock, saying that the plan to sell certain assets was "designed to navigate Anglo to a more manageable gearing level".
"We could not have asked for a bigger or more detailed plan, but now we move to timely execution," analysts at Deutsche Bank said in a note.
The UK mining sector <.FTNMX1770> is up around 37 percent since mid-January, when it hit 12-1/2 year lows.
Retailer Sainsbury rose 4.3 percent, also benefiting from a target price upgrade. Exane BNP Paribas lifted the grocer to "outperform" from "neutral", saying that the market under-appreciated the potential benefits from its recently agreed deal to buy Home Retail .
AstraZeneca rose 1.7 percent after the U.S. Food and Drug Administration granted breakthrough therapy designation to its biggest new drug hope durvalumab as a treatment for bladder cancer.
(Reporting by Alistair Smout; Editing by Mark Heinrich)