The preparations of the bidbook include work package 5 (BB-WP5 Communications); this includes three products that are closely related, both in process and output; 1. Optimal European positioning and presentation of the EMR as a candidate site; 2. ET-EMR Bidbook writing and effective communications to decision makers and unfluencers; 3. Stakeholder communications; decision makers and supporting influencers and public; Note; These products and activities are additional to the environmental management and spokesmanship already in place to stakeholders in the Euroregion. 1. Optimal European positioning and presentation of the EMR as a candidate site; 2. ET-EMR Bidbook writing and effective communications to decision makers and unfluencers; 3. Stakeholder communications; decision makers and supporting influencers and public;

Dear Sir/Madam, The contracting authority hereby informs you that the following European open tender procedure has been withdrawn: Tender title: Product Manager Bidbook WP5-Communications Tender reference: TN517855 Contracting authority: Nikhef, on behalf of the ET-EMR Project Office This decision is taken in accordance with Sections 3.6.1 and 3.6.2 of the Procurement Guide (P2.1_126_V1.0, dated 16-04-2025), which state that: • this invitation to tender does not constitute a contract and no rights may be derived from it (Section 3.6.1); • the contracting authority reserves the right, without liability or obligation for compensation, to suspend or abort the tender procedure or decide not to award the contract at all (Section 3.6.2). In this case, the contracting authority has reassessed internal priorities and project needs and decided not to proceed with an award under this tender. We sincerely thank the interested parties for their efforts. Kind regards, John Kerstjens Project Control T +31 6 34 84 76 67 Einstein Telescope - Euregio Meuse-Rhine W www.einsteintelescope-emr.eu.