In their statement, the lawyers did not provide an amount but the companies have already said that they have set aside 5 billion rand ($395 million) in provisions for the settlement.

That has already been reflected in financial results and so it should not impact future earnings.

The companies involved are Harmony Gold, Gold Fields, African Rainbow Minerals, Sibanye-Stillwater, AngloGold Ashanti and Anglo American. The latter no longer has gold assets but historically was a bullion producer.

"The settlement is the product of commercial negotiation and compromise, but we believe this is a beneficial settlement," said Carina du Toit, a lawyer with the Legal Resources Centre, one of the law groups representing the workers.

Abrahams Kiewitz Inc and Richard Spoor Attorneys also represented the mine workers.

The class action suit was launched six years ago on behalf of miners suffering from silicosis, contracted by inhaling silica dust in gold mines.

The settlement still needs approval by the Johannesburg High Court before being implemented.