To promote travel by the underground railways in London a joint marketing arrangement was agreed that included maps, joint publicity and through ticketing. UNDERGROUND signs were used outside stations in Central London. The UERL acquired London bus and tram companies in 1912 and the following year the City & South London and Central London Railway joined the company. That year the Great Northern & City was taken over by the Met. Suggestions of merger with the Underground Group were rejected by the Metropolitan, a press release of November 1912 noting its interests in areas outside London, its relationships with main line railways and its freight business. Further coordination in the form of a General Managers' Conference faltered after the Metropolitan withdrew in 1911 when the Central London Railway, without any reference to the conference, set its season ticket prices significantly lower than those on the Met's competitive routes. The UERL introduced station name boards with a red disc and a blue bar and the Met responded with station boards showing a blue bar on a red diamond.