South Africa's logistics group Transnet is looking for private bidders to operate 7,300 km of its railway lines, the company said in a newspaper advertisement.

Transnet has said it would open up its lines to private investors in a bid to speed up upgrades to its ageing fleet.

Coal exporters have criticized 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 advert in the Business Day newspaper said. The company said earlier this year it expected the government to endorse a framework for private sector participation in its project pipeline by the end of 2010. (Reuters)