According to Art. 42b of the Swiss Cartel Act, data may only be disclosed to a foreign competition authority based on an act, an international agreement or with the consent of the undertaking concerned. Without the consent of the undertaking concerned, the competition authorities may disclose confidential data, in particular business secrets, to a foreign competition authority on the basis of an international agreement only if: According to Art. 42b of the Swiss Cartel Act, data may only be disclosed to a foreign competition authority based on an act, an international agreement or with the consent of the undertaking concerned. Without the consent of the undertaking concerned, the competition authorities may disclose confidential data, in particular business secrets, to a foreign competition authority on the basis of an international agreement only if: a. the behaviour under investigation in the recipient state is also unlawful under Swiss law; b. both competition authorities are investigating the same or related behaviour or transactions; c. foreign competition authority uses the data only for the purpose of applying provisions of competition law or as evidence in relation to the subject matter of the investigation for which the competition authority requested the information; d. the data is not used in criminal or civil proceedings; e. the foreign procedural law safeguards party rights and official secrecy; and f. the confidential data is not disclosed to the foreign competition authority in the context of an amicable settlement or when assisting in the discovery and elimination of the restraint of competition. COMCO has to notify the undertaking concerned and invite it to state its views before transmitting the data to the foreign competition authority. According to Art. 7 para 3 of the agreement between the European Union and the Swiss Confederation concerning cooperation on the application of their competition laws (EU Agreement;  available here: Legislation (admin.ch) DG Comp and COMCO may transmit information in their possession to each other when the undertaking which provided the information has given its express consent in writing. When such information contains personal data, those personal data may only be transmitted when the competition authorities of the Parties are investigating the same or related conduct or transaction. In the absence of a consent, the competition authority of a Party may, upon request, transmit for use as evidence information obtained by investigative process that is already in its possession to the competition authority of the other Party, subject to the following conditions:  (a) information obtained by investigative process may only be transmitted where both competition authorities are investigating the same or related conduct or transaction;  (b) the request for such information shall be made in writing and shall include a general description of the subject matter and the nature of the investigation or proceedings to which the request relates and the specific legal provisions involved. It shall also identify the undertakings subject to the investigation or procedure whose identity is available at the time of the request; and  (c) the requested competition authority shall determine, in consultation with the requesting competition authority what information in its possession is relevant and may be transmitted.