GLOBAL MARKETS-Shares advance, investors hope for Greece progress

* Stocks earlier fell as lenders failed to agree on Greece * Euro and U.S. dollar flat; Japanese yen rebounds * Brent oil edges higher on Middle East tension By Ryan Vlastelica NEW YORK, Nov 21 (Reuters) - World shares advanced on Wednesday as policymakers in Europe reassured markets that a deal on releasing emergency aid to Greece was close, though the failure of lenders to come to an agreement on their own kept investors cautious. Euro zone finance ministers, the International Monetary Fund and the European Central Bank will gather again Monday, after nearly 12 hours of talks overnight in Brussels failed to produce a consensus on how to shrivel Greece's debt. After the meeting ended,...