Edison Telephone Co
1879 The Edison Telephone Company of London Ltd, was registered 2 August, and opened in London 6 September 1879[1].
1880 Brought legal action against the India Rubber, Gutta Percha and Telegraph Works Co for alleged infringement of Mr. Edison's patent for carbon telephone transmitters. [2]
1880 United Telephone Co formed from The Telephone Company (Bell's Patents) Ltd and The Edison Telephone Company of London. [3].