YOU could never accuse Sam Jonah, boss of Ashanti, one of the world’s biggest goldmining groups, of lacking a sense of humour. “Here,” he smiles, when I walk in to his firm’s City of London office, “you’ll be interested in this.” He hands me a fax from the government of Zimbabwe, congratulating him on his honorary knighthood, conferred by Prince Charles last month.

He watches me while I read. When I look up, a big grin is creasing his pouchy cheeks and there is a distinct twinkle in his heavy-lidded eyes. Jonah, 53, Ghanaian by birth and now one of Africa’s best-connected business leaders, cannot resist the tease.

“Zimbabwe is not quite,” he pauses, savouring his own grasp of idiom, “flavour of the month round here, is it? Hahaha.” And he gives a deep, rumbling laugh that seems to roll round the room.

Charm, mischievous humour and diplomatic cunning have long been the Jonah hallmarks in a business career that has seen him head Ashanti for 17 years. In that time he has transformed it from a former Lonrho subsidiary that operated one highly valuable mine in Ghana, into a multinational with interests across Africa and the first black African company to be listed on the London Stock Exchange, likewise on the New York market. He is also, still, the world’s only black goldmining boss.

This year it looks like he is making another step change. Ashanti has spent the best part of three months in merger talks with AngloGold, the South African-based Anglo American subsidiary that is the world’s second-biggest goldmining company. Put the two together, and you create the world’s No1, a title currently held by the American giant Newmont.

The “merger” looks, in effect, like a takeover by AngloGold, which is offering its shares as collateral, and giving Ghana’s government a say over the new company’s Ghanaian interests — although the delays in the merger talks suggest the politicians in Accra may already have cold feet about selling one of the country’s biggest business assets.

And what position will Jonah take in the new entity if the talks prove fruitful? “I have a broad spectrum of options,” he says, spreading his arms.

Could he not, for instance, be a very useful black voice on the board of the parent company Anglo American, once pilloried for its closeness to South Africa’s apartheid regime and now under pressure to increase black Africans’ stake in its goldmining business? He smiles and repeats: “I have a broad spectrum of options.” Then he laughs infectiously again.

Broad, bulky, balding, occasionally dabbing his domed forehead with a handkerchief as if still in sweaty Accra, Jonah likes to play his cards close to his chest. He won’t comment on the merger delays but will point out that size counts now in the goldmining industry. Consolidation gives the survivors more power over the price of gold, hence more stability for employees in the long term, and greater access to capital and know-how. Ashanti, he says, has an unparalleled track record in training and advancing black managers, and in maintaining the best mining practices and high safety standards, and can transfer those skills.

It wasn’t always that way. Jonah was one of eight children. His father was a soldier-turned-construction boss, his mother a businesswoman, and he was brought up next to the Obuasi goldmine in Ghana. “My father used to say: ‘You misbehave, you’ll be sent down there as a punishment’.” Conditions were terrible. Migrant black workers were bussed in from the north. White managers ran everything.

Yet affluent Ghanaians accepted that as best practice. “My father also used to say, ‘the day a black man runs those mines, I’m leaving Obuasi’.” When Jonah ended up head of the mine, he teased his father about whether he would still leave. “He said, ‘The white people call you master? I bet behind your back they still call you a big black bastard’.”

Cue that laugh again. Jonah is absolutely upfront about the racism endemic in African life, knowingly spinning off stories that non-Africans might find difficult to recount, yet always leavening a serious message with British-style irony.

One banker remembers him standing up at a mining conference in America a decade ago, saying that Ashanti had always been in favour of more consolidation in the industry, pausing then adding: “and I want you to think of me as your white knight”. The audience loved it.