The guarantee will help Transnet to raise funds in the markets for GE's share of its massive Rand 50bn order for 599 electric and 465 diesel locomotives which was announced in March.
"This is a massive thumbs-up from the international investor community, affirming Transnet's creditworthiness and South Africa's attractiveness as an investment destination," Transnet group chief executive Mr Brian Molefe said last week.
The funds – to be raised through bank loans backed by the guarantee – will be drawn down over three years as the locomotives are built. The repayment period is 14 years.
The locomotive deal is a key component of Transnet's fleet renewal programme, which falls under the company's seven-year Rand 312bn Market Demand Strategy.
Most of the locomotives will be built at Transnet Rail Engineering facilities, in line with the company's long-term ambition to become an original equipment manufacturer.
The new GE locomotives will be based on the company's successful Evolution Series product platform.