Glencore began a process to sell its Lomas Bayas copper mine in Chile late last year, when anxiety about the health of some mining firms’ balance sheets was high. A deal could not be reached partly because Glencore did not get the price it was looking for, the sources said, speaking on condition of anonymity. Further, Glencore feels it is in a stronger footing and is not compelled to make a sale at any cost, the sources said.

While it is always still possible that Glencore changes its mind or a potential buyer makes a much better offer, the company has decided to keep the asset for now, the sources said. The Swiss-based mining and trading firm, which reports results later this month, declined to comment. Glencore's official position has not changed since a presentation in Miami in May when it said it expected to complete asset sales in the second quarter. It said they would include a mixture of Lomas Bayas and Cobar copper assets, additional monetization of precious metals and G Rail infrastructure in Australia.

Glencore has also said it would only sell assets at the right price. "Glencore definitely has some pressure off them. That gives them more time and more negotiation power," said David Neuhauser, managing director at U.S. hedge fund Livermore Partners, a Glencore shareholder. "We just want the capital structure to come in line so it's sustainable and it can withstand any shocks to the system," he said.

Situated in the Atacama desert, Lomas Bayas is an open pit copper mine in Chile that produces about 75,000 tonnes of copper cathode a year. Some analysts have valued the mine at about $500 million. Interest in the Lomas Bayas mine came from Magris Resources Inc, a private equity firm run by former Barrick Gold Corp CEO Aaron Regent, as well as other PE firms and mining companies, the sources said. Glencore conducted a process that involved three rounds of bids, receiving multiple offers for each round, one of the sources said. The price of copper has been largely stagnant since the start of the year and analysts are largely bearish because of a supply overhang.

On Thursday, Glencore revised up its guidance for full-year copper production following strong performance across several assets. Glencore shares have more than doubled since the start of the year, echoing strong gains across the mining sector.

(Reporting by John Tilak in Toronto, Barbara Lewis in London and Sonali Paul in Melbourne; Editing by Bernard Orr)

By John Tilak and Barbara Lewis