The London General Omnibus Company or LGOC, was the principal bus operator in London between 1855 and 1933. It was also, for a short period between 1909 and 1912, a motor bus manufacturer.
In 1912, the Underground Group, which owned most of the London Underground, bought the LGOC. In 1933, the LGOC, along with the rest of the Underground Group, became part of the new London Passenger Transport Board.
More information on the Wikipedia page [1]. The London Remembers page is [2].