The Malawi unit of Bharti Airtel switched on its 3G network yesterday, as part of the Indian firm’s push to expand in fast-growing Africa. The Bharti unit – one of the 15 African mobile networks it acquired from Zain earlier this year – is the largest in Malawi. According to a Reuters report, Bharti plans to spend US$100 million in the next three years on network expansion in the country.