Dr Hans Diekmann


Hans advises on M&A transactions including public takeovers as well as on corporate and capital markets law. 

German DAX and MDAX companies, financial institutions and large listed companies count among his regular client base.

In addition to his M&A work Hans Diekmann advises his clients inter alia on annual shareholders' meetings, capital market law (including investigations by Bundesanstalt für Finanzdienstleistungsaufsicht), initial public offerings, corporate reorganisations as well as on general corporate law advice and on financing issues. He also regularly advises executives and board members on matters relating to corporate compliance.

JUVE ranks him as one of Germany’s 15 leading senior corporate Partners.


Representative matters

City of Hamburg regarding the contemplated joint venture with MSC in HHLA Aktiengesellschaft.

Uniper SE regarding the stabilization package and capital measures to ensure Germany's gas supply.

Elmos Semiconductur SE regarding the sale of its waver fab to littlefuse.

RAG foundation, one of the largest German foundations, as part of a consortium under the lead of private equity investors Advent and Cinven, on the acquisition of the elevator business from thyssenkrupp AG. Transaction volume: EUR17.2bn.

Friede Springer and Mathias Döpfner on the public takeover of Axel Springer SE by KKR (including delisting offer in 2020). Transaction volume: EUR6.8bn.

Uniper SE on the hostile takeover bid by Finnish energy company Fortum.

A global financial services provider on a bancassurance agreement with a multinational financial institution for the distribution of life and non-life insurance products for individuals and small-businesses in a number of Eastern European countries.

Several listed companies (amongst them, Axel Springer SE, alstria office REIT-AG, Uniper SE, IKB Deutsche Industriebank AG, Elmos Semiconductor SE) on their annual general meetings and on various corporate and capital markets law matters.

Several companies (amongst them, BASF AG, Elmos Semiconductur SE, EON AG, Fresenius AG, Deichmann, Dürr Dental AG) on the conversion of their legal form into an SE.

Published Work

  • Diekmann, “Kommentierung des Geschäftsführers, des Aufsichtsrats und sonstiger Organe”, in: Münchener Handbuch des Gesellschaftsrechts, Band 3: Gesellschaft mit beschränkter Haftung, 6. Aufl. 2023, C.H.BECK
  • Diekmann, “SE-VO Art. 4 – 8 und SE-VO Art. 15, 16”, in: Habersack/Drinhausen, SE-Recht, 4. Aufl. 2024, (erscheint demnächst) C.H.BECK
  • Diekmann, “Kommentierung der §§ 60 – 77 zur Verschmelzung unter Beteiligung von Aktiengesellschaften sowie der §§ 141 – 146 zur Spaltung unter Beteiligung von Aktiengesellschaften und Kommanditgesellschaften auf Aktien”, in: Semler/Stengel/Leonard, Umwandlungsgesetz, 6. Aufl. 2024 (erscheint demnächst), C.H.BECK 
  • Diekmann, “Entstehung einer Europäischen Aktiengesellschaft (Societas Europaea, SE) durch Verschmelzung zur Aufnahme” (Ziffern 5.01 und 5.02), in: Happ/Bednarz, Umwandlungsrecht, 2. Aufl. 2021, Heymanns Verlag GmbH

Speaking Engagements

  • External teacher in Jur Grad Münster/Westf., Take-over law (Wertpapierübernahmegesetz).

Leadership Positions And Professional Affiliations

  • Member, VGR Wissenschaftliche Vereinigung für Unternehmens- und Gesellschaftsrecht
'Leading senior partner', 'Fast, sound assessments'.
(Client), JUVE 2018/2018
Very dedicated and always available
(Client), “Band 2.” Chambers 2019


  • The Legal 500, Germany Awards, Corporate and M&A, lawyer of the year 2024.



Admitted as German Rechtsanwalt, 1993


Second German Law Degree, Düsseldorf, 1992

Dr iur, University of Münster/Westphalia, Germany, 1990

First German Law Degree, Hamm/Westphalia, 1988


A&O Shearman was formed on May 1, 2024 by the combination of Shearman & Sterling LLP and Allen & Overy LLP and their respective affiliates (the legacy firms). Any matters referred to above may include matters undertaken by one or more of the legacy firms rather than A&O Shearman.