An EC regulation was agreed in December 1989 under which mergers between companies may be vetted by the Commission rather than Member States: this will happen where there is a Community dimension because of the size of the turnover of the companies involved and their substantial presence in more than one Member State. Such vetting is necessary to ensure that the new companies created by mergers do not enjoy monopolies. Companies which have to seek Commission approval should not also have to get clearance from their governments as well, which is why this is sometimes known as "one-stop shopping".