Business Leadership South Africa (BLSA) has suspended the membership of state entities Eskom and Transnet with immediate effect.
The decision follows "extensive allegations of corrupt behaviour"‚ the business lobby group said.
BLSA CEO Bonang Mohale said in a statement: "South Africans have been rightly disturbed in recent times at the numerous allegations of corrupt behaviour and colossal failures of corporate governance and accountability at both Eskom and Transnet."
BLSA said it had engaged with Eskom and Transnet over the allegations but had found both wanting.
"Neither of the SOEs were able to give BLSA comfort that they appreciated the seriousness of the issues at hand‚ or that they had the requisite will and purpose to put their houses in order. This left BLSA with no choice but to suspend their memberships from the organisation. We have to live by our values and will take a zero-tolerance approach to any organisation found in breach."
A series of high-level officials have come under scrutiny at Eskom and Transnet over their alleged links to state capture‚ in particular using their position to hand lucrative contracts to the politically connected Gupta family.