British mobile phone giant Vodafone on Tuesday said its first-half net loss doubled to more than 5.0 billion euros owing to a huge writedown for its Indian unit.

Vodafone said its loss after tax soared to 5.1 billion euros ($5.5 billion) in the six months to September 30 compared with a net loss of 2.5 billion euros one year earlier, following an impairment charge of 6.4 billion euros "in respect of the group's investment in India".