"Investments by Eskom, Transnet and the SA National Roads Agency Limited [Sanral] account for 90% of this amount," according to 2014 Budget Review, tabled by Finance Minister Pravin Gordhan on Wednesday.
The SOEs play a major role in government's public infrastructure investments, which would reach R847bn over the next three years.
In his budget speech, Gordhan said: "The first unit of the Medupi power station is expected to be completed by the end of this year."
Investment in the country's rail services would also be boosted.
While Transnet was planning to increase capacity on its coal, manganese and iron ore lines, investment in commuter rail services would continue to be steadily expanded.
"The Passenger Rail Agency of South Africa [Prasa] refurbished 500 Metrorail coaches last year, and its new rolling stock procurement programme will get underway this year," Gordhan said.
The performance levels of SOEs when it came to delivering on infrastructure commitments was improving.
In 2012/13, SOEs spent close to 80% of their budgeted funds, compared to 70% the previous year.
The public Enterprises department will get R259m to monitor and oversee the SOEs.