The BBC said Russell’s appointment was a step back against transformation.
BBC chairman Sello Rasethaba said the country had more capable black men and women who could have taken over from Mophatlane.
“Isaac (Mophatlane) could have been replaced by a black professional from the company. But chairman Jabu Mabuza and chief executive Themba Maseko preferred to replace Mophatlane with a white man,” Rasethaba said.
“It is a demonstration that they do not care about BEE. They are encouraging the exodus of black executives from Telkom.”
Mophatlane resigned abruptly on Tuesday, but will leave the parastatal in three months.
Rasethaba said the BBC believed he was forced out.
“There’s no magic solution to avoid the hurt feelings, the tension, the discomfort this development has caused among our members. This is an attack on black excellence,” said Rasethaba, adding the BBC would approach Post and Telecommunications Minister Siyabonga Cwele to intervene because the government is a majority shareholder.
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Telkom said Mophatlane would be a consultant to group chief executive Sipho Maseko in the coming three months to ensure a seamless transition.
Mophatlane founded BCX with his late brother Benjamin almost 20 years ago (it was called Business Connection then), before it was sold to Telkom in 2015.
Industry experts were also shocked by Mophatlane’s sudden departure.
Peter Takaendesa, a portfolio manager at Mergence Investment Managers, said the industry was surprised by the departure of Mophatlane from the company, as he was recently retained as the chief executive when they rebranded the company to BCX from Telkom Business Connexion.
“We do not have all the details on the reasons for his departure, but purely from a business point of view we believe he is leaving the company he founded in a much stronger position as a combined entity with Telkom Business,” said Takaendesa.
“The combined entity (BCX) provides both technology and telecommunications services to most of South Africa’s large enterprises.
"But Telkom has to ensure that BCX will not lose its empowerment credentials, which we believe are necessary for the long-term sustainability of the business,” said Takaendesa.
Jordan Weir, equities trader at BayHill Capital, said it was a disappointment to see a founding member leave a business.