Zimbabwe's Econet Wireless, the country's largest mobile phone operator, has reported a 16 percent increase in half-year earnings, mainly driven by subscriber growth.

Earnings per share rose to $0.44 in the six months to end-August, up from $0.38 in the same period last year, Econet said in a statement. The firm's after-tax profit was $74 million, up from $64.3 million previously.

Econet, which has over 70 percent share of Zimbabwe's mobile phone market, said its subscriber numbers stood at 5.5 million at the close of the half year, up from 4.6 million previously.

Revenues jumped 24 percent to $290.9 million, from $235.5 million last year.

Econet said it has spent $470 million on network expansion since 2009, when Zimbabwe adopted the use of foreign currencies, mainly the United States dollar and South Africa's rand to replace a local unit destroyed by hyperinflation.