Telkom, Africa's biggest phone firm, has thanked a reduced wage bill and strong growth at mobile subsidiary Vodacom for a 50% rise in profits.
Telkom is Africa's largest phone company
Releasing its results for the half-year to 30 September, it made a pre-tax profit of 7bn rand ($1bn; £596m), up from 4.7bn rand for the year before.
Revenues were ahead by 9.9% at 23.5bn rand, up from 21.3bn a year earlier.
Vodacom, co-owned with UK phone firm Vodafone, saw its customer base increase by 42% during the period.
Vodacom now has 19.1 million users and is benefiting from economic growth in South Africa that is boosting consumer spending power.
Revenues at Telkom's fixed-line phone business increased by 4.3%, helped by a rise in data services.
Telkom shares were floated on the Johannesburg Stock Exchange in March 2003, but the group remains majority state-owned.
Vodafone held 35% in Vodacom until the start of this month when it bought an additional 15% stake from investment firm Venfin.