The power cuts will continue until 5 a.m. on Friday after which they will be brought back down to around two hours.

The longer power cuts, which are termed level four load shedding locally, require the company to take off at least 4000 megawatts (MW) from the national grid, approximately 10% of its total generating capacity.

"It was anticipated that an additional seven units would have returned to service by Monday, and this has not materialised," the debt-laden company said, adding another unit at a power station had gone out of service.

The company, which operates 15 coal-fired power stations and has a total nominal capacity of roughly 46,000 MW of power generation, said total breakdowns currently amounted to 14,874 MW and an additional 5,579 MW was off grid due to planned maintenance.

(Reporting by Promit Mukherjee; Editing by Mark Potter)