JOHANNESBURG (AFP) - South African billionaire Patrice Motsepe announced Monday he would give half his family's fortune to a charity, matching a pledge made by Bill Gates and Warren Buffett.

"This is to be used during his lifetime and beyond... to improve the lifestyles, and living conditions, of poor, disabled, unemployed, women, youth, workers and marginalised South Africans," his wife Precious Motsepe said.

Motsepe owns mining company African Rainbow Minerals and is Africa's eighth richest person with a fortune of US$2.65 billion (S$3.3 billion), according to Forbes magazine.

The mining tycoon becomes the first African to join the Giving Pledge, which challenges the world's wealthiest to give 50 per cent or more of their fortune to charity.

Since Microsoft mogul Gates and investment guru Buffett launched the Pledge in 2010, more than 70 billionaires have joined.

His announcement, two days after his 51st birthday, makes him part of an illustrious club that includes Facebook founder Mark Zuckerberg, Netflix chief executive Reed Hastings, and Intel co-founder Gordon Moore.