Vietnam's ambitious state-run telecoms operator Viettel launched mobile and internet services in Tanzania after investing $736 million in East Africa's second-biggest economy.

Tanzania's mobile telecoms sector has grown rapidly over the past decade, driven by demand for third-generation (3G) mobile services. The number of mobile phone subscribers in Tanzania rose by 16 percent in 2014 to 31.86 million, according to the country's telecoms regulator.

A statement issued by Viettel, which is run by Vietnam's Ministry of Defence, said the company will trade as Halotel in Tanzania and would offer both 2G and 3G services.

"With an initial investment of $736 million ... Viettel’s operations have enabled services to all 26 regions in the country across rural and urban areas," it said.

"Viettel's new investment in Africa follows the rollout of services in Burundi and Cameroon ... earlier this year and in Mozambique ... in 2014."

Viettel said it had built 18,000 km of optical cable and more than 3,000 base transceivers, giving it coverage for up to 81 percent of Tanzania’s population of over 47 million.

The company will compete with four other main operators in Tanzania: Vodacom Tanzania, owned by South Africa's Vodacom, Bharti Airtel, Tigo Tanzania, which is part of Sweden's Millicom and Etisalat - owned Zantel.

Three other mobile operators - state-run TTCL, Benson and Smart - have a small market share.
The Tanzanian president's office said last year Viettel plans to invest $1 billion in a new 3G mobile phone network in the country.

Like other African countries, mobile phone use has rocketed in Tanzania over the past decade, with telecoms the fastest-expanding sector in the country.

Viettel operates in markets in Asia, Latin America and Africa, and has around 75 million subscribers worldwide, according to its website. Its revenues in 2014 were $9.8 billion and it is aiming for a 20 percent increase in 2015.