Updated

Nigeria has fined four mobile phone carriers a total of $7.3 million over poor service and call quality in Africa's dominant market.

Reuben Muoka of the Nigeria Communications Commission said Sunday that Bharti Airtel Ltd. of India, Abu Dhabi-based Etisalat, local firm Globacom Ltd. and South Africa-based MTN Group Ltd. all had been fined.

Muoka said in a statement that the companies were fined over performance in March and April. Muoka said mobile phone operators had poor service in January and February, but were given a grace period.

In October, regulators warned mobile phone operators that they could be fined over their poor service. In Nigeria, those who can afford it carry mobile phones from different companies to be able to make a call.