The net loss before tax came in at 5.5 billion rand ($385.55 million) in the year ended Dec. 31, from a loss of 4.1 billion rand in 2019.

The country's fourth-biggest mobile operator booked an impairment of 5.1 billion rand. The once-off costs include recapitalisation costs of 434 million rand and network site restorations costs of 248 million rand, Cell C said.

Excluding the impairment, the net loss after tax would have been 380 million rand, it said.

Total revenue was down by 8% as its prepaid subscriber base, its largest revenue contributor, declined by 15% to 9.2 million customers as the carrier shifts away from unprofitable customers to boost returns.

"The company's strategy of focusing on more profitable customers is bearing fruit as the average revenue per prepaid customer (ARPU) has increased by 28% on a year-on-year basis," Cell C said.

($1 = 14.2653 rand)

(Reporting by Nqobile Dludla; Editing by Promit Mukherjee and Louise Heavens)