France's Financial Markets Authority (AMF) has published guidance on how to declare trading in the securities of companies that are the subject of a public offer, setting out the reinforced transparency and strictly framed intervention rules that apply from the announcement of an offer’s characteristics through to the end of the offer period. The AMF makes available a website file listing all companies listed on Euronext Paris and Euronext Growth for which a public offer has been announced but not yet filed with the AMF (pre-offer period) or has been filed (offer period). The reporting and intervention rules apply to securities of companies on this list and, where the offer consideration includes securities of the offeror, also to the offeror’s securities. Transactions carried out during the offer period must be declared no later than the next trading day using the relevant AMF form (Type I or Type II, depending on the declarant’s status under the AMF General Regulation) and accompanied by a signed headed cover letter; the AMF also points to its Q&A on proprietary trading by investment services providers during offer periods (AMF position DOC-2009-22).