Proventis Partners advises Zwahlen et Mayr S.A. on Fairness Opinion for Public Takeover

PRESS RELEASE

Zurich, 18 September 2025 – Proventis Partners advised the Board of Directors of Zwahlen et Mayr S.A. as Fairness Opinion provider on the public tender offer by SITINDUSTRIE Suisse SA for the outstanding shares of Zwahlen et Mayr S.A.

The Transaction

On 18 September, Zwahlen et Mayr S.A. (ZM) announced that SITINDUSTRIE Suisse SA, a company of Groupe Bader SA, intends to increase its stake in ZM to 100% by launching a voluntary public tender offer for all remaining shares of ZM listed at the SIX Swiss Exchange. SITINDUSTRIE Suisse SA’s objective is to acquire all shares of ZM and subsequently delist the company. This transaction forms part of the Group’s strategy of sustainably growing the company within the new group structure by unlocking synergies and reducing complexity and associated costs.

About Zwahlen et Mayr S.A.

Since 1979, Zwahlen & Mayr has been a leading manufacturer of welded stainless steel and nickel-alloy tubes under the brand ZM Tubes. By 1990, Zwahlen & Mayr began producing drawn stainless-steel tubes and, in 2021, expanded into seamless tubes. The tubes are manufactured in Aigle, near Lake Geneva, and are 100% Swiss-made. Thanks to continuous investments in machinery and employee training, ZM Tubes is internationally recognized for its high-quality products, excellent customer service, and reliability in critical applications.

The Role of Proventis Partners

Proventis Partners provided an independent Fairness Opinion to the Board of Directors of Zwahlen et Mayr S.A. to assess the financial fairness of SITINDUSTIRE Suisse SA’s voluntary public tender offer. The Proventis Partners team consisted of Jan Wetter (Partner), Christoph Studinka (Partner), Christophe Zimmerli (Partner), Raffael Dubach (Associate), and Philippe Hänni (Analyst).