The London Stock Exchange Group plc is the leading diversified stock exchange group in Europe. It owns the Borsa Italiana and London Stock Exchanges. It is a member of the FTSE 250 Index as of 21 June 2010.
The London Stock Exchange was founded in Sweeting's Alley in London in 1801. It moved to Capel Court the following year.
In 1972 the Exchange moved to a new purpose-built building and trading floor in Threadneedle Street. Deregulation, sometimes known as "big bang", came in 1986 and external ownership of member firms was allowed for the first time. In 1995 the Alternative Investment Market was launched and in 2004 the Exchange moved again, this time to Paternoster Square.
Nasdaq built up a stake of over 30% in the Exchange in 2007 in a failed attempt to acquire it. It has since sold its investment.
In 2007 the Exchange acquired the Milan-based Borsa Italiana for 1.6bn euros (£1.1bn; $2bn) to form the London Stock Exchange Group plc. The combination was intended to diversify the LSE's product offering and customer base. The all-share deal diluted the stakes of existing LSE shareholders, with Borsa Italiana shareholders receiving new shares representing 28 per cent of the enlarged register.
On 16 September 2009, the London Stock Exchange Group agreed to acquire Millennium Information Technologies, Ltd., a Sri Lankan based software company specialising in trading systems, for US$30m (£18m). The acquisition was completed on 19 October 2009.