South African state-owned logistics group Transnet plans to increase its capacity to haul iron ore from mines to ports by 56 percent over the next seven years, its Chief Executive Brian Molefe said on Tuesday.

Molefe also said Transnet, whose wagons carry 53 million tons of iron ore currently, would increase its capacity to move coal from mines to ports from 68 million tons to 97.5 million tons over the same period.

Transnet recently tripled its capital investment programme to 300 billion rand ($38.09 billion)over seven years to expand infrastructure in Africa's biggest economy, where bottlenecks on rail lines and at ports have slowed exports and economic growth.

Transnet moves commodities such as coal, iron ore and fuel.