Filing: China-based Transsion, which commands 53% of Africa's mobile phone market by unit sales, is seeking to raise as much as ~$428M in a Hong Kong share sale (Sangmi Cha/Bloomberg)

Sangmi Cha / Bloomberg: Filing: China-based Transsion, which commands 53% of Africa's mobile phone market by unit sales, is seeking to raise as much as ~$428M in a Hong Kong share sale — Shenzhen Transsion Holdings Co., which dominates the market for smartphones in Africa, is seeking to raise as…