By Wendell Roelf

CAPE TOWN (Reuters) - China's Huawei, the world's third-largest smartphone maker, will launch its new cheaper Nova smartphone in South Africa and Kenya early next year, looking to maintain double-digit sales growth in the continent led by its flagship P9 series.

Challenging the dominance of Samsung and Apple, the world's number one and two, Huawei has targeted 140 million smartphone sales globally in 2016 from 100 million last year, and sees Africa as a key market in attaining its ambitious goal.

"Our figures for mobile phones have been doing extremely well in major markets like Nigeria, Kenya and South Africa in particular this year," Roland Sladek, vice president international media affairs, told Reuters on the sidelines of an African communications conference.

Smartphone sales growth was in double-digits, although Huawei is not releasing exact figures yet, he said.

Last year a senior official said the company expected to double its 2014 smartphone sales to 2 million in South Africa alone over 12 months.

Huawei is keen to take advantage of Africa's smartphone growth potential, which analysts suggest will continue to boom as cheaper phones accelerate penetration that could rise from about 79 million at end 2012 to 412 million by 2018.

The new Nova mid-range phone, launched globally at a German trade fair in September, is expected to cost significantly less than the 12,000 rand ($842) price tag of its P9 model, aimed more at Africa’s tech-savvy students.

"We see huge potential, not only with a rising middle class, but also the fact that consumers are more open to try new brands compared to the Europeans who stick to their brands," Sladek said.

Having made its name as a builder of telecommunications networks, Huawei has been active in the consumer devices market for only a few years.

Besides boosting its smartphone market footprint in Africa however, Huawei is building network infrastructure across the continent particularly for the faster 4G, and expected to complete a new 6,000 km sub-sea broadband cable linking Cameroon to Brazil by the end of 2018.

"The first phase is finished," Sladek said.

The largest submarine cable Huawei has built to date, its initial 32 terabytes per second capacity is expected to enhance Internet connectivity in the West African region.

Huawei had a 9 percent share of the global smartphone market in the third quarter, according to research firm Strategy Analytics. Apple was still well ahead with a 12 percent market share and Samsung had a market share of 20.1 percent.

(Editing by James Macharia and Alexandra Hudson)