Miner Xstrata has been given a deadline of 5.00pm on 20 October 2009 to make a formal bid for Anglo American or otherwise to walk away.The put-up or shut-up ruling follows an appeal by Anglo to the Takeover Panel over the disruption to its business caused by the interest from Xstrata.In June, Anglo American's board turned down Xstrata's proposal of a nil premium as not being in the best interests of its shareholders. In its statement today it said ' The board stated that it considered the strategic case for the combination to be unattractive for Anglo American and, furthermore, the terms proposed by Xstrata to be totally unacceptable. Nothing since then has changed the board's view and the board reiterates its emphatic rejection of Xstrata's approach'.