Annual General Meeting 2026 Supplementary information on agenda item 4: Résumés of the candidates for election to the Supervisory Board

KLÖCKNER & CO SEI ANNUAL GENERAL MEETING 2026

Name Residence Year of birth Place of birth

Prof. Dr.-lng. Dieter H. Vogel

Düsseldorf 1941

Cheb (Czech Republic)

Nationality German

Occupation/profession Chairman of the Company's Supervisory Board,

Managing Partner of Cassiopeia GmbH

Studied mechanical engineering at TU Darmstadt (Dipl.-Ing.) and doctorate at TU Munich (Dr.-lng.)

1970-1975 Bertelsmann AG

Last position held: Deputy Chief Executive Officer ofTechnical Operations

1975-1985

1980-1985

1986-1998

1999-2020

Pegulan Werke AG

Last position held: Chief Executive Officer British American Tobacco Deutschland Deputy Chief Executive Officer Thyssen AG

Last position held: Chief Executive Officer Lindsay Goldberg Vogel GmbH

Founder and Managing Partner

Prof. Dr.-lng. Vogel has been Chairman of the Company's Supervisory Board since its I PO 2006. He has an outstanding knowledge of the steel industry and steel trading with over 40 years of experience as a member of management and supervisory bodies in a wide scope of enterprises (among others ABB AG, Deutsche Bahn AG, Bertelsmann SE & Co KGaA and Stiftung, Freenet AG, in each case Chairman of the Supervisory Board).

Klöckner & Co SE (listed), Chairman of the Supervisory Board and its Presidium

• denkwerk GmbH {unlisted), Member of the Advisory Board

• HSBC Continental Europe S.A., Germany branch (unlisted), Member of the Advisory Board

None

Supplementary information on agenda item 4

Name Residence Year of birth Place of birth Nationality

Prof. Dr. Tobias Kollmann Cologne

1970

Bonn German

Occupation/profession Professor of Digital Business and Digital Entrepreneurship at the University of Duisburg-Essen

Education

Studied economics at the Universities of Bonn and Trier (Dipl.-Volkswirt) and doctorate at the University of Trier (Dr. rer. pol.)

Career

1997-2001 Activity in the start-up/venture capital practice:

• particularly support for Scout24 Holding (Switzerland) in the development of virtual marketplaces

• in the course of this, among other things, co-founder of AutoScout24 GmbH as one of the founding shareholders

ZOO1-Z005 Christian-Albrechts-University of Kiel Chair of E-Business

Z005-Z0Z4 University of Duisburg-Essen

Chair of Digital Business and Digital Entrepreneurship

Special knowledge and experience for Supervisory Board service

Prof. Dr. Kollmann was among the pioneers of the German internet economy and electronic marketplaces. He is also a recognized digitalization expert with numerous publications in the field, in particular on

Digital Business and Digital Entrepreneurship. In addition, he has an excellent network in politics and in the start-up and venture capital sector.

I lembership in domestic statutory supervisory boards Klockner & Co SE (listed), Member of the Supervisory Board

I lembership in comparable German or foreign corporate supervisory bodies None

Other significant activities Managing Partner of netSTART GmbH

This document is a convenience translation of the German original.

In case of discrepancy between the English and German versions, the German version shall prevail.

KLÖCKNER & CO SEI ANNUAL GENERAL MEETING 2026

Name Residence Year of birth Place of birth

Prof. Dr.-lng. E. h. Friedhelm Loh

Dietzhölztal 1946

Weidenau

Nationality German

Occupation/profession Entrepreneur, Owner and Chairman of Friedhelm Loh Stiftung & Co. KG

Apprenticed electrician (high voltage) and studied business administration

1974-1989

Since 1989

Rittal GmbH & Co. KG

Partner and Chief Executive Officer Friedhelm Loh Stiftung & Co. KG Owner and Chief Executive Officer

Prof. Dr.-lng. E. h. Loh is an indirect major shareholder in the Company. As a successful entrepreneur, he has many years of experience in the management of large companies. He is very well connected in business and politics.

Klöckner & Co SE (listed), Member of the Supervisory Board

None

None

Supplementary information on agenda item 4

Name Residence Year of birth Place of birth Nationality

Uwe Rohrhoff Monchengladbach 1962

Monchengladbach German

Occupation/profession Chief Executive Officer of Gerresheimer AG

Education

Studied business administration at the University of Cologne (Dipl.-Kfm.)

Career

1989-1991 Scheidt & Bachmann GmbH

Finance and Accounting 1991-2017 Gerresheimer AG

Last position held: Chief Executive Officer

2018 Perrigo Company plc.

President and Chief Executive Officer

Since 2019 Independent Consultant and member of several supervisory boards Since 11/2025 Chief Executive Officer of Gerresheimer AG

Special knowledge and experience for Supervisory Board service

Uwe Rohrhoff has extensive and longstanding experience in management positions and the management of large companies, including positions abroad. Due to these experiences and his service on various supervisory boards, he is familiar with the work of supervisory bodies and has, among other things, expertise in the

field of auditing, also with respect to sustainability reporting and its audit and assurance. He is also already familiar with the Company from his previous service as member and Deputy Chairman of the Supervisory Board.

I' lembership in domestic statutory supervisory boards Klockner & Co SE (listed), Chairman of the Audit Committee

I lembership in comparable German or foreign corporate supervisory bodies

• Constantia Flexibles GmbH, Vienna, Austria (unlisted), Member of the Supervisory Board

• Rochling SE & Co. KG (unlisted), Member of the Advisory Board (dormant since November 1, 20Z5)

Other significant activities None

This document is a convenience translation of the German original.

In case of discrepancy between the English and German versions, the German version shall prevail.