In 1973, in response to concerns about the costs of securing patent protection in Europe, the European Patent Convention was signed to set up a common patent office to examine patent applications for any European country that wished to participate. Once examination was complete, the application matured into a bundle of national patents in those countries in which the applicant was interested. The convention went into effect in 1978 with the opening of the European Patent Office. Two years after the European Patent Convention was signed, a further treaty, the Community Patent Convention, was signed with the objective of creating a unitary patent for what was then the European Economic Community and a system in which such patents could be litigated. The Community Patent Convention never came into effect because of concerns about the languages to be used and the way in which the litigation system would work.