Metropolitan-Vickers Electrical Co Ltd was the new trading name given to British Westinghouse Electric and Manufacturing Co on 8 September 1919. The predecessor company had sold its controlling share to the Metropolitan Carriage Wagon Co in 1916 in order to gain membership of the Federation of British Industries. In 1919, Vickers acquired the Metropolitan Carriage Wagon Co, along with its controlling share in British Westinghouse, prompting the change in name to Metropolitan-Vickers Electrical Co Ltd. The American owned British Westinghouse had established its English operations at Trafford Park in 1899, and Metropolitan-Vickers Electrical Co Ltd continued on the same site from 8 September 1919. The company was initially known for its electricity generators, later diversifying into the manufacture of steam turbines, switchgear, transformers, electronics and railway traction equipment. The passing of the Electricity (Supply) Act in 1926 provided a boost to the company’s post-war fortunes, with the creation of the National Grid generating demand for the company's products. In 1928, Metropolitan-Vickers Electrical Co Ltd merged with its rival British Thomson Houston Co Ltd, retaining both names for trading purposes. The following year, on 4 January 1929, Associated Electrical Industries Ltd (AEI) acquired Metropolitan-Vickers Electrical Co Ltd and the British Thomson Houston Co Ltd. Again, both trading names were retained, and a fierce rivalry was established between the firms which the parent company was unable to control. In 1931, Sir Felix Pole joined Metropolitan-Vickers Electrical Co Ltd as its new chairman. He oversaw a period of expansion for the company leading into the Second World War. In 1939, seeking a more concise name for the company, the Board of Directors decided upon Metrovicks, which became interchangeable with the official company name of Metropolitan-Vickers Electrical Co Ltd. Under Sir Felix Pole's chairmanship, Metropolitan-Vickers developed new products for the aviation industry and during the war was one of the sites where Lancaster bombers were built. In 1941, the company developed the first British axial-flow jet engine, the Metrovick F.2. Following the Second World War, the company appointed Oliver Lyttelton as chairman, with the aim of increasing the efficiency and productivity of AEI. Despite his success in achieving this aim, Lyttelton was unable to resolve the commercial rivalry between Metropolitan-Vickers Electrical Co Ltd and the British Thomson Houston Co Ltd. During his second period as chairman, from 1954-1963, Lyttelton, now Lord Chandos, oversaw the development by Metropolitan-Vickers Electrical Co Ltd of the first commercial transistor computer, the Metrovick 950. Chandos also resolved to extinguish the competition and internal divisions between Metropolitan-Vickers Electrical Co Ltd and the British Thomson Houston Co Ltd, and both company names ceased to be used from 1 January 1960, with all subsidiaries going on to trade under the name of Associated Electrical Industries Ltd.

Mather & Platt Ltd (M&P), Newton Heath was established when Colin Mather entered into a partnership with William Platt in 1852. Prior to this, in 1836, Colin Mather had entered into a partnership with his brother William, trading as William & Colin Mather, Brown Street, Salford. The brothers later leased part of the Salford Iron Works from John Platt in 1845 and entered into partnership with him. John Platt died in 1847, and his son William continued in the partnership with William and Colin Mather. In 1851, the partnership between William and Colin Mather was dissolved and the following year Colin Mather formed the partnership with William Platt that created M&P. Colin Mather's brother William died in 1858, and his son, also called William, became assistant manager of the company in the same year. In 1863, William Mather became a partner with his uncle Colin Mather and William Platt. Colin Mather and William Platt retired around 1868, and William Platt's son John joined the company. He became a partner with William Mather in 1878. William Mather travelled around the world promoting the company. During a trip to the United States in 1883 he obtained rights to manufacture Thomas Edison’s electric dynamo. Dr John Hopkinson and his brother Edward, who became head of the company’s new Electrical Department, modified the design to produce the famous Edison-Hopkinson dynamo, also known as the Manchester dynamo. M&P became highly regarded as manufacturers of centrifugal pumps. In 1873 Osborne Reynolds, Professor of Engineering at Owen’s College, designed an innovative turbine pump. M&P went on to manufacture this pump for use in water works, collieries, mills and power stations. In 1883 M&P obtained the exclusive rights to manufacture a new automatic sprinkler system, patented by Frederick Grinnell. The rights to manufacture this sprinkler system, outside North America, would prove to be a crucial turning point in the company’s fortunes. There was an enormous market for the Grinnell system in the textile industry where mills were at considerable risk from fire. A Bolton based firm, Dowson Taylor and Company, manufactured the sprinkler heads under licence, until it formally joined M&P in 1896. John Taylor’s expertise formed the basis of M&P’s hugely successful Fire Engineering Department. As the company’s business expanded in the last quarter of the nineteenth century the Salford Iron Works was enlarged. In 1873 the company acquired Drinkwater’s Mill in Deal Street and absorbed the whole of Foundry Street. Mather and Platt became a private limited company in 1892. In 1900 the company purchased a larger site at Newton Heath in Manchester. The company gradually moved its operations over to a purpose-built factory called Park Works, which had better access to the railways and waterways. Park Works expanded, eventually incorporating a canteen, a research laboratory, a school and a sports ground. The iron foundry was the last part of the Salford Iron Works to be moved before the old factory was finally sold in 1938. During the First World War part of the Park Works factory was leased to aircraft manufacturers A V Roe & Co Ltd. In 1915 the entire works came under the control of the Ministry of Munitions, as a result of the Munitions of War Act, 1915 in order to increase munitions production. The Russian Revolution in 1917 had a profound effect on the company’s export of textile machinery to textile mills in St Petersburg and Moscow. The company had created a Russian company to deal with the large numbers of orders and expand its business however, it lost control of the company and did not receive compensation until the 1980s. Sir William Mather died in 1920. Aside from his business career he had played an active role in politics and civic life. He began his parliamentary career as Liberal MP for Salford in 1885. He went on to represent the constituencies of Gorton and Rossendale in the House of Commons before retiring from politics in 1904. He was knighted in 1902 and served as a Privy Councillor from 1910. His son Loris took over the business and guided it through the turbulent years of the Great Depression. During the Second World War, Park Works was once again brought under Government control with M&P not only producing munitions, but also pumps for the war effort. Some of the equipment manufactured at the Park Works was shipped to the Soviet Union for use on the Eastern Front. After the war ended M&P relocated its Food Machinery Department to the former Royal Ordnance factory at Radcliffe in order to make more space at the Park Works. After the initial economic austerity of the immediate post-war period, this side of the business expanded with increased consumer demand for foodstuffs in the 1950s. As M&P held the exclusive licence for manufacturing the Grinnell sprinkler system the company enjoyed a dominant position in this lucrative market. However, when these rights expired in the 1970s the firm entered terminal decline in a climate of increased competition from abroad. In 1978, the company was taken over by the Australian-based company Wormald International. Wormald International was originally founded by Joseph and Harry Wormald whose brother John worked for Dowson Taylor and Company. Today an Indian company continues to manufacture pumps under the M&P name as a subsidiary of the German multinational Wilo A.G.