Raymond Chirwa, the chief executive of South Africa's Richards Bay Coal Terminal (RBCT) is expected to resign on Wednesday, online service miningmx.com reported on Tuesday, citing unnamed industry sources.

Neither Chirwa nor his office could immediately be reached for comment.

RBCT has recently completed an expansion of the terminal to handle up to 91 million tonnes of coal, but has been unable to use the full capacity due to bottlenecks on the rail lines linking the terminal with coal mines in the country's Mpumalanga province.