Mining mega-merger off as Rio Tinto digs heels in

RIO TINTO'S courtship of Glencore is over after Rio declined to make a formal play for some or all of Glencore's assets.

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A diverse set of mining properties and compelling strategic fit made for an attractive combination on paper.

But as with all relationships, there's no set formula for chemistry and the gaps between the two parties have been too big to reconcile.

Just how Glencore's coal and trading arms would fit into Rio's business model, and how they would push for improved sustainability credentials, were among the issues to address. However, the more fundamental questions of valuation and who holds the remote control have been the main points of disagreement.