JOHANNESBURG/ LONDON (Reuters) -BHP Chief Executive Mike Henry said that Anglo American investors need to consider the merits of his company's bid for its smaller London-listed rival, seeking to drum up support for a proposal that has been rejected twice.

The CEO of the world's biggest listed mining group told investors at a metals and mining conference in Miami that Anglo shareholders must make a "determination" on the benefits of a combination of the two companies and which team they think has a better track record of executing projects and delivering returns to investors.

Anglo CEO Duncan Wanblad on Tuesday outlined plans to refocus on energy transition metal copper while spinning off or selling its less profitable coal, nickel, diamond and platinum businesses.

Henry, meanwhile, emphasised the merits of BHP's $43 billion bid and dismissed concerns that the proposed deal would be complex to execute.

"At the end of the day, it's going to be up to shareholders. They have to look at the plans, decide which one they believe is going to create the greatest value soonest," he said.

"And they have to make a determination as to the likelihood of execution of those plans, including which team they believe is more capable and has a better track record of execution. It's that simple."

The Anglo board argues that the proposed deal undervalues the company and is difficult to execute, with BHP planning to demerge two of Anglo's South African assets prior to a takeover.

BHP chief Henry, however, says the company has sufficient experience to execute complex transactions, having divested South32 assets in South Africa.

Henry said he was disappointed with the Anglo board's continued refusal to engage, adding that BHP would have preferred to continue talking in private.

"Our strong preference was to be able to hold these discussions with Anglo in private," Henry said. "Rather unfortunately, it got leaked."

While BHP is intent on growing its copper business, it would maintain its disciplined approach to capital allocation, Henry said, adding that the copper industry remains fragmented.

"We do not take capital discipline lightly, we will remain disciplined and we have demonstrated that in previous instances," he said.

($1 = 0.7953 pounds)

(Reporting by Felix Njini and Clara DeninaEditing by David Goodman)