JOHANNESBURG (Reuters) - A lawyer acting for nearly half a million miners who contracted fatal lung diseases silicosis and tuberculosis in mines said an out-of-court settlement was expected to be signed on Thursday with those gold companies implicated in the issue.

The High Court in 2016 set the stage for protracted proceedings on cases dating back decades in the largest class action suit yet in Africa’s most industrialized country.

“Barring unforeseen circumstances, we expect to sign the silicosis agreement with the gold industry tomorrow (Thursday),” Richard Spoor told Reuters on Wednesday.

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

The settlement, which would also cover those who contracted from tuberculosis, would still need approval by the High Court before being implemented.

The Occupational Lung Disease (OLD), a group put together by the six companies involved, could not be reached for comment.

South African gold producers say they have set aside 5 billion rand ($398 million) in provisions for the settlement.

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