The world's biggest mobile phone company is facing a series of lawsuits brought by brain tumour victims in the US.

The cases, filed by one of America's most successful lawyers, will herald the most extensive examination of the health implications of mobile phone use.

Each of the cases names a mobile phone handset manufacturer, a network provider and a local "landline" provider. Verizon Wireless, Vodafone's US joint venture with Bell Atlantic, is named in nearly all the cases.