Acting Transnet Chief Executive Chris Wells told reporters the company was on course to achieve 81 million tonnes in annual exports within the next five years, while it had also signed contracts to expand iron ore export capacity to 60 million tonnes from the current 44.7 million tonnes.

Transnet data showed that export of coal declined by 0.2 percent to 61.8 million tonnes in the year to end March 2010 from 61.9 million tonnes in the previous year.

"We are investigating together with the coal industry moving beyond 81 million tonnes and looking forward to the future of possibly 90-100 million tonnes and it depends on the economics of that feasibility study," Wells said.

Wells said the industry planned even bigger export capacity for iron ore and the company was looking at shipping more exports through Luanda in Angola and Maputo in Mozambique.

"We are in a detailed planning phase, for the next expansion. The players are looking at going beyond 80 million tonnes (capacity for iron ore)," Wells said.

Exports of iron ore rose to 44.7 million tonnes, in line with customer commitments, compared with 36.8 million tonnes in the previous financial year, while container volumes declined by 4.5 percent to 3,629, following a contraction in global trade due to the economic recession, he said.

"The economic environment we operated in was very difficult, it was an unpredictable start to the year. We are determined to turn that around," Wells said.

"We will need private sector participation to some extent to ensure those projects take off," Wells said.

Coal exporters have criticised state-owned Transnet for failing to transport all of their coal to the port at Richards Bay due to lack of investment and derailments on the lines.

The lines would be operated under a concession deal with Transnet retaining the ownership, the company said.