From Graces Guide
Makers of vulcanised electric light wires and cables, of Norfolk House, Victoria Embankment, London, WC (in 1918), and, Bush House, Aldwych, London, WC2 (in 1935).
1883 The company began life as an agent for the US Western Electric company that also had a factory in Antwerp, Belgium. The London operation sold US-designed telephones and exchanges to fledgling British telephone companies.
1898 A failing cable factory at North Woolwich in London’s East End was acquired. Despite setbacks, this factory made lead-sheathed cables and also assembled equipment from components imported from Belgium and the United States. It then moved into complete manufacture as well.
1906 Installed the Post Office's first coin-operated call box at Ludgate Circus, London.
1910 Incorporated as a limited company to take over a business which had already been trading for some years. It was then a wholly-owned subsidiary of the International Western Electric Co. of the U.S.A.
1910 Using advanced American thinking and designs and after incorporation as a British legal entity, Western Electric’s future looked bright.
1914 The Post Office installed a Western Electric Company rotary-type automatic telephone exchange at Darlington. It was similar to the Lorimer system in the use of power-driven selector switches but included a device to receive the subscriber's signals from a rotary tenhole dial and to store them for subsequent control of the switches.
1914 Manufacturers of and dealers in telephone, electric light and power cable, telephone apparatus etc. 
WWI The company contributed to the war effort in military communications and the, then primitive, cable and wireless technologies they used. Radio technology was being initiated in the neutral USA. This gave Western Electric a post-war advantage as wireless broadcasting was introduced in Britain.
1916 Another telephone exchange was installed at Dudley. In 1922, the Post Office adopted the Strowger system as its standard and the rotary-system was not deployed further on the network.
1920s The company was closely involved in wireless broadcasting (radio).
1921 Patent relating to electrical connectors
1922 Cable factory at North Woolwich before moving to a new factory.
1922 With 5 other telecommunications companies the company set up the British Broadcasting Company (later Corporation) as well as producing wireless receivers. Valve technology was developed and commercially exploited.
c.1923 Started the manufacture of valves and also of radio sets.
1925 The International Western Electric Co was acquired by ITT; these interests were transferred to the International Standard Electric Corporation of New York. Its British subsidiary's name was changed to Standard Telephones and Cables Ltd..