A bailout for struggling South African state utility Eskom could reach as much as R150-billion over ten years, a senior National Treasury official told Reuters.

The Treasury said on Wednesday that it would provide Eskom with R69-billion of financial support over three years.

But Ian Stuart, a senior official at the budget office, told Reuters that Treasury had included in its national debt-to-gross domestic product projections a further R23-billion of annual support to Eskom after that three-year period.

The final amount of support would depend on factors including economic growth, demand for electricity and the rate of reorganisation at Eskom, Stuart said.