Mining giant BHP Billiton abandoned its yearlong pursuit of acquiring its rival Rio Tinto on Tuesday, saying that the mega-merger would be too risky amid the turmoil in the financial markets and regulatory concerns in Europe.

BHP had offered 3.4 of its shares for each share in London-based Rio Tinto, valuing the smaller company at about $60 billion. Although sharp falls across the world’s stock markets have depressed the original value of the deal, Rio Tinto has rejected BHP’s offer as inadequate.

Objections from European antitrust regulators for the proposed all-share takeover appeared to be a key issue affecting the transaction that would have been one of the largest takeovers ever.

Tim Baker, resources analyst at BT Financial Group told Reuters: “This decision suggests that BHP’s board have looked at what’s going on in the market and realized the situation is not quite what it was before because of the economic deterioration.”

In a statement filed to the Australian Securities Exchange, BHP Billiton expressed concern that given the sharp drop in commodities prices and global turndown, it was uncertain whether it would be able to reap fair value for the assets that the European Commission wanted it to divest.

BHP said it no longer believed “that completion of the offers for Rio Tinto would be in the best interests of BHP Billiton shareholders.” The company, based in Sydney, Australia, added that “greater debt exposure of the combination plus the difficulty of divesting assets have increased the risks to shareholder value to an unacceptable level.”