Ad hoc announcement pursuant to Art. 53 LR

Baar, Switzerland, 18 September 2025

Michael Reitermann, Member of the Board of Directors since 2020, and an executive leader with broad experience both in the USA and Europe, has been appointed by the Board of Directors of Ascom Holding AG as Delegate of the Board of Directors and interim CEO. He takes over the operational leadership from Nicolas Vanden Abeele, who decided to leave Ascom after nearly four years as CEO to pursue new professional challenges.
The Board of Directors of Ascom Holding AG nominated Laurent Dubois, Member of the Board of Directors since 2020, as new Chairman of the Board of Directors to be elected at the Annual General Meeting 2026, following the retirement of Dr. Valentin Chapero Rueda.

Michael Reitermann appointed as Delegate of the Board and interim CEO
While pursuing the current strategy, the Board of Directors of Ascom Holding AG targets to accelerate its execution and the exploitation of the growth potential of Ascom, with a special focus on the USA and Canada. Michael Reitermann, Member of the Board of Directors since 2020, has been appointed as Delegate of the Board of Directors and interim CEO to take over the operational leadership of the Ascom Group for a limited time period. In parallel, an internal and external search for a new CEO has been initiated.
Michael Reitermann is an accomplished executive with more than 25 years of commercial and technical expertise in the med-tech/life sciences space in both the USA and Europe. He was the CEO of several entities of Siemens Medical Solutions, and later, the COO and member of the managing board of Siemens Healthineers. Michael Reitermann is living in the USA and has a German/American dual citizenship.
The Board of Directors expresses its sincere appreciation for the departing CEO, Nicolas Vanden Abeele, for his dedicated service during challenging times and for his valuable contributions to the transformation of the Company.

Laurent Dubois nominated as new Chairman of the Board
The Board of Directors nominated Laurent Dubois, Member of the Board since 2020, as new Chairman of the Board to be elected at the Annual General Meeting 2026, following the retirement of Dr. Valentin Chapero Rueda, effective as of the Annual General Meeting 2026.
Laurent Dubois has over three decades of leadership experience in industry, consulting, B2B technology, and healthcare. He was a partner with McKinsey & Co. and later joined GE Healthcare, where he led the global solutions & analytics teams as a member of the Global Executive Team. Since 2020, he has been CEO of ADB Safegate, a Carlyle portfolio company and global leader in airside guidance technology.

Moreover, the Board of Directors decided to reduce its size from six to five members, effective as of the Annual General Meeting 2026.

Note   (www.ascom.com/about-us/who-we-are/board-of-directors)

• CV Michael Reitermann
• CV Laurent Dubois

Conference Call for analysts and media
In the context of this media release, a conference call for analysts and media will take place as follows: 
18 September 2025 at 09:00 CET
Dial-in: +41 58 262 07 22 / Code: 030955