General Motors head of African operations has given an upbeat assessment of prospects for the company's sales in sub-Saharan Africa.

Speaking at a Reuters event in Johannesburg, GM Africa managing director Mario Spangenberg said that there is a

“huge opportunity” for growth in the countries positioned between South Africa and Northern Africa.

Reuters reported that Spangenberg said annual vehicle sales in Africa will rise nearly 20% in the next two years to hit the 2m mark as the continent's burgeoning middle class increases demand for new cars.

The report said that GM sold 180,000 vehicles on the continent last year, giving it a 10 percent market share and putting it narrowly behind rival Toyota which recorded African sales of 237,000.

The report said that of GM's total sales, 100,000 went to North Africa and 70,000 to South Africa, leaving only 10,000 to sub-Saharan Africa in between.

"That's where we see the huge opportunity for growth," GM Africa managing director Mario Spangenberg told the Reuters Africa Investment Summit in Johannesburg.

Spangenberg told Reuters that GM hopes to increase its market share with models such as the Isuzu pick-up, which has proved resilient to Africa's rugged conditions.

"We want to defend our 10 percent and maybe grow it a little bit," he said.

Of Africa's 40-odd sub-Saharan frontier markets, Nigeria is the most attractive prospect, Spangenberg said.