343Lastly, the applicant submitted, in reply to the written questions put by the Court, that, in the light of the principles of equal treatment and proportionality, double punishment for the same conduct is as unjust in parallel proceedings as in sequential proceedings. That argument cannot be accepted. Where two penalties are imposed by the same authority in a single decision, that authority can ensure that, taken together, the penalties are proportionate, and the court can also verify the proportionality of the penalties taken together (see paragraph 342 above). The imposition of two penalties for the same conduct, by the same authority in a single decision cannot therefore be considered, as such, to be contrary to the principles of equal treatment and proportionality.