Gold major Barrick Gold chairperson John Thornton has urged shareholders to vote in favour of its $6.1-billion transaction with Africa-focused Randgold Resources, telling investors that the combined entity will have five of the world’s ten so-called tier-one assets and that this could be expanded in a short space of time.

In a conference call discussing the group’s third-quarter results, Thornton outlined how the merged company could add another four mines to its list of tier-one assets, defined as those producing more than 500 000 oz/y, with a minimum mine life of ten years and in the lower half of the cash cost curve.

The four potential tier-one assets waiting in the wings are Fourmile and Turquoise Ridge, in Nevada, Veladero, in Argentina and Acacia Mining’s North Mara mine, in Tanzania.

Bloomberg News previously reported that the assets that do not meet the tier-one criteria include Lagunas Norte in Peru, Canada’s Hemlo, a 47.5% share of the Porgera mine, in Papua New Guinea, a 50% stake in Kalgoorlie in Australia, and Golden Sunlight in Montana.

Analysts believe that Barrick’s copper mines could be on the block, with Lumwana, in Zambia, having been cited as a potential asset that could be sold. Thornton responded that copper remained a strategic mineral, particularly for Chinese companies, and that Barrick would always have copper in its portfolio as the mineral often appears with gold.

However, in the long term, he said Barrick could consider trading copper assets for gold ones and indicated that this was of "high interest" to its partners in Saudi Arabia and China.

"We are engaged with both of them, what you might call sort of slow motion, long-term conversations about how to maximise the value of things," he said.

Shareholders are set to vote on the Barrick-Randgold transaction at a November 5 meeting. ISS and Glass Lewis have recommended to both sets of shareholders that they should vote for the transaction, which will see industry veteran Mark Bristow take the helm of the enlarged company.

"I'm hard-pressed to think of a chief executive in any industry that's had the two-decade long record that Mark has had, much less a chief executive in the gold mining industry, much less one in the gold mining industry in Africa," Thornton said, noting that the combination of tier-one assets and a strong leadership created a "compelling investment proposition".

Since the transaction was announced last month, Barrick's shares have risen 25% and Randgold’s stock is up 28%, compared with senior gold peers’ stock that advanced about 3%.