Partner

Dr. Sebastian Orthmann, EMBA (M&A)

Rechtsanwalt | Co-Head of the Real Estate Group

Languages

German
English
Spanish

Social media

Sebastian Orthmann advises national and international investors and project developers on the acquisition and sale of companies, and the acquisition and sale of real estate and real estate portfolios in Germany and abroad in the form of asset deals and share deals. He also specialises in advising on joint ventures, corporate structuring measures, project development, commercial lease law and financing. His clients include institutional investors, private equity investors, banks, asset managers, family-owned companies, public authorities and companies from various sectors.

Sebastian joined CMS in 2004 and has been a partner since 2011. He has a degree in Real Estate Economics (ADI) and has been a lecturer at IR│EBS for many years.

Awards & Recognitions

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Listed for Real Estate

Deutschlands beste Anwälte 2025 – Handelsblatt in Kooperation mit Best Lawyers
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Listed for Corporate

Deutschlands beste Anwälte 2025 – Handelsblatt in Kooperation mit Best Lawyers
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Listed for Mergers and Acquisitions

Deutschlands beste Anwälte 2025 – Handelsblatt in Kooperation mit Best Lawyers
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Listed as notable practitioner

Chambers Germany, 2025
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„Oft empfohlen“ für Immobilien- und Baurecht

JUVE Handbuch, 2024/2025
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„erstklassige Beratung u. sichere lösungsorientierte Verhandlungsführung“, Mandant

JUVE Handbuch, 2024/2025
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Listed for Real Estate

Deutschlands beste Anwälte 2024 – Handelsblatt in Kooperation mit Best Lawyers
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Listed as notable practitioner

Chambers Europe, 2024
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‘Sebastian Orthmann has impressive knowledge. He is very fast and always responds promptly.‘, client

Chambers Europe, 2024
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‘He is very professional, provides clear recommendations and possesses strong negotiation skills.‘, client

Chambers Europe, 2024
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„sehr guter, erfahrener Transaktionsanwalt“, Mandant

JUVE Handbuch, 2023/2024
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„Oft empfohlen“ für Immobilien- und Baurecht

JUVE Handbuch, 2023/2024
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Listed as notable practitioner

Chambers Europe, 2023
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Listed as leading individual

Chambers Europe, 2023
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Listed for Real Estate

Deutschlands beste Anwälte 2023 – Handelsblatt in Kooperation mit Best Lawyers
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Listed for Corporate

Deutschlands beste Anwälte 2023 – Handelsblatt in Kooperation mit Best Lawyers
Quote

Listed for Mergers and Acquisitions

Deutschlands beste Anwälte 2023 – Handelsblatt in Kooperation mit Best Lawyers
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"Sebastian Orthmann comes 'warmly recommended' by a client who notes that he 'supported us extremely well'."

Chambers Europe, 2021
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Listed as notable practitioner

Chambers Europe, 2021
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"excellent support in examining complex real estate issues, solution-oriented", client

JUVE German Commercial Law Firms 2021 (GCLF)
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"very competent", client

JUVE German Commercial Law Firms 2019 (GCLF)
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"Hamburg-based Sebastian Orthmann, who is singled out for his ‘in-depth knowledge’ and ‘thorough work’ […]."

The Legal 500 EMEA, 2018
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„Zuletzt stemmten auch die Energie- u. Immobilienpraxen (Dr. Sebastian Orthmann) große Transaktionen […].“.

JUVE Handbuch, 2017/2018
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"Clients speak highly of Sebastian Orthmann due to his ability to "concentrate on the main topics and give good feedback on minor points that can be skipped," adding: "He knows how to make the process efficient."

Chambers Europe, 2018
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"Sebastian Orthmann has a strong focus on transactions involving shopping centres. He regularly advises on both share and asset deals. "

Chambers Europe, 2017
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"Sebastian Orthmann focuses on real estate M&A deals, and is especially visible in the retail sector."

Chambers Europe, 2016
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"Up-and-coming Sebastian Orthmann focuses on transactions in the real estate sector, in particular to do with acquisitions of retail and residential properties."

Chambers Europe, 2015
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"Sebastian Orthmann handles corporate law issues and transactions for real estate investors. His clients say: ‘He looks for a solution that is useful rather than just theoretical.’"

Chambers Europe, 2014
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"deal-oriented and yet precise", competitor

JUVE German Commercial Law Firms 2014 (GCLF)
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"Recommended" for Real Estate

JUVE German Commercial Law Firms 2022 (GCLF)
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"Sebastian Orthmann delegates to members of his team as far as they are able to fulfill the corresponding task. This is in the interest of everyone involved. At the same time, he remains informed about the matter and can be contacted directly. That’s how it should be.", client

The Legal 500 EMEA, 2022
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"Sebastian Orthmann’s CMS team is extremely conscientious, but at the same time accessible to practical solutions. The consultancy is obviously driven by performance in terms of content and not by maximizing profits.", client

The Legal 500 EMEA, 2022
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„Oft empfohlen“ für Immobilien- und Baurecht

JUVE Handbuch, 2022/2023
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"he has a very good overview on the whole transaction process and it is easy to work with him.", client

Chambers Europe, 2022
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Listed as Leading Individual

Chambers Europe, 2022
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Notable practitioners

Chambers Europe, 2022

Relevant experience

abrdn | Sale of an office property in Frankfurt.
Barings | Acquisition and sale of various logistics sites, including project development and asset management, most recently advised on the sale of a leased logistics property in Sarstedt to Clarion.
Berenberg | Acquisition of various office and mixed-use properties.
CLS | Acquisition and sale of various office properties.
DSR | Sale of various hotel properties as sale-and-leaseback.
ECE | On acquisition and sale of various shopping centres in Germany and other European countries (asset and share deal); advice on the negotiation and conclusion of a hotel lease agreement.
Fleming's | Sale and letting of various hotel properties.
Franklin Templeton | Acquisition and asset management of office properties in Dortmund and Frankfurt.
GRR | Sale of more than 150 discounters, specialist retailers and shopping centres in Germany, most recently advised on the sale of 23 local shops to Peakside and Stoke Park.
Hermann Friedrich Bruhn | Ongoing advice on various acquisitions, sales and project developments of office, retail, hotel and residential premises.
Hyperscaler | Acquisition and project development of four data centres in Germany with several 100mw capacity.
IVG Immobilien | Sale of TRIUVA shares to PATRIZIA.
Gator | Sale of three office properties and one residential property in Hamburg in a structured bidding process (asset and share deal with leaseback).
Panattoni | Acquisition and development as well as sale of various logistics properties.
Phoenix Contact | Acquisition of various companies.
Principal Real Estate | Acquisition of a data centre and its asset management in Frankfurt.
Ramboll | Acquisition of various companies and structuring of German group companies.
Swiss Life | Establishment of joint ventures; acquisition, project development and sale of various logistics locations (seed portfolio).
Unilever | Change of location: termination of Unilever-Haus lease agreement and new lease in Hamburg; sale of parts of the company premises in Heilbronn.
Union Investment | Advising on the takeover of investment companies of Austrian Volksbanken.
Union Investment Real Estate | Acquisition of several shopping centres in Germany and Italy (asset deal and share deal) in single and portfolio transacitons.
Universal-Investment | Acquisition (share deal) of a high street portfolio consisting of 90 objects from German and Luxembourgish companies; acquisition of various other retail, office and residential properties in Europe and Asia.
Warburg-HIH | Acquisition and sale of various office and retail properties.

Publications

Haftung und Insolvenz im GmbH-Recht, Kapitel B.IV. zum Kapitalersatz gemeinsam mit Dr. Nancy Gruschinske, Hrsg. Holzborn/v. Vietinghoff, München 2013, S. 82ff
Leitfaden für die Bestellung von Sicherheiten im Rahmen von Bankdarlehen gemeinsam mit Philipp Weber, BB 2012, S. 1039ff
Forum Mergers & Acquisitions 2011, Nachvertragliche Wettbewerbsverbote im Unternehmenskaufvertrag zu Lasten eines Gesellschafter-Geschäftsführers gemeinsam mit Dr. Till Soyka, Hrsg. Wollersheim/Barthel, Wiesbaden 2011, S. 95ff
Bewertung von Bestandsimmobilien durch Immobilieninvestoren nach HGB und IFRS im Lichte der Finanzkrise, Bewertung von Bestandsimmobilien durch Immobilieninvestoren nach HGB und IFRS im Lichte der Finanzkrise, Hrsg. Birk/Bruse/Saenger 2010, p. 131 ff
Fair-Value-Ermittlung bescherte bisher Gewinne, Immobilienzeitung vom 1. Oktober 2009, p. 39
Sri Lanka (k)ein Steuerparadies für ausländische Investoren?, RIW 2004, p. 682 ff
Betriebliche Altersversorgung im Jahresabschluss nach HGB,US-GAAP und IAS, Tenea Verlag 2003
Buchbesprechung zum "Praktiker-Handbuch zur Umsetzung der betrieblichen Altersversorgung" von Dr. Axel Schack, Karsten Tacke, Dr. Jens T. Thau, Betriebs-Berater 2003, p. 43

Lectures list

Update Immobilienrecht: Gesetzesänderungen, Trends & Handlungsempfehlungen, IMMOEBS-Webinar, Webinar, 2026-01-27
Joint Ventures in der Immobilienentwicklung – zwischen Partnerschaft und Pragmatismus, Real Estate Forum von Feldhoff & Cie., Hamburg, 2025-06-12
Restrukturierung im Immobilienbereich, Roadshow, Hamburg, 2025-04-08
Update Immobilienrecht: Schriftformerfordernis, IMMOEBS-Webinar, Webinar, 2025-01-14
Projektentwicklungschancen in Hamburg, Real Estate Forum von Feldhoff & Cie., Hamburg, 2024-06-27
Kommerzielle Alternativen - Life Sciences, Rechenzentren und Gesundheitswesen sind die nächste Wette?, Deutsche GRI 2024, Frankfurt, 2024-05-16
Immobilien in Zeiten der Energiewende, CMS-Mandanten-Veranstaltung, Hamburg, 2023-07-05
Fußball und Renditen: Hamburg nur noch zweitklassig?!, Real Estate Forum von Feldhoff & Cie., Hamburg, 2022-06-28
Umnutzungspotenzial Innenstadt, CMS-Mandanten-Webinar, Online, 2021-06-01
Panelist bei PropertyEU am 12.11.2020 zum Thema: Resetting Real Estate: Covid-19 and the rise of ESG and social purpose
Feldhoff Real Estate Forum Hamburg 2020 am 24.09.2020, Interview zum Thema "Quartiersmanagement der Zukunft: Vom Marketing zum Community Building"
Chair zum Thema Build To Rent Resi – Cradle to grave, goldmine or mid market pocket? bei der GRI in Paris (September 2019)
Feldhoff Real Estate Forum Hamburg 2019 am 18.06.2019, Podiumsdiskussion zum Thema "Commercial Real Estate"
Moderator zur Veranstaltung Künstliche Intelligenz, smart Date und Digitalisierung in der Immobilienwirtschaft 2019 (Mai 2019)
Conferencier der Veranstaltung PropTech – Die Zukunft der Immobilienbranche ist digital in Berlin (März 2019)
Vortrag Rechtliche Trends auf dem europäischen Immobilien-Investmentmarkt 2018 (CMS European Real Estate Deal Point Study 2018) (November 2018)
Moderator eines Panels zu ICOs bei der Future PropTech in Berlin (September 2018)
Feldhoff Real Estate Forum Hamburg 2018, Podiumsdiskussion zum Thema "Der Projektentwicklungsmarkt Hamburg"
Feldhoff Real Estate Forums Hamburg 2017 am 11.07.2017, Podiumsdiskussion zum Thema "Der Hamburger Investmentmarkt"
Conferencier der Veranstaltung PropTech in Berlin (November 2016)
Moderator des Real Estate Forums 2016 in Hamburg (Juli 2016)
Moderator des Seminars Akzeptanz schaffen - Bürgerbeteiligung bei Bauprojekten (Juni 2016)
Moderator der CMS Real-Estate-Investorenkonferenz in Frankfurt (März 2016)
LawUpdate für Investmentberater: Trends in der Vertragspraxis bei Immobilientransaktionen (Februar 2016)
Vorstellung der CMS European M&A Study 2015 - Neueste Ergebnisse (April 2015)
Moderator der CMS Real-Estate-Investorenkonferenz in Frankfurt (Februar 2015)
Vorstellung der CMS European M&A Study 2014 - Neueste Ergebnisse (April 2014)
Marktentwicklungen im Immobilientransaktionsmarkt in Deutschland, Kopenhagen, November 2012
Vorstellung der CMS Real Estate Deal Point Study 2011, Gestärkter Immobilienmarkt - aktuelle Entwicklungen, November 2011
Strukturierung von Joint Ventures und deren Fallstricke, Regionaltreffen der RICS und ADI Alumni, Mai 2011
Vorstellung der CMS Real Estate Deal Point Study 2010, Oktober 2010
Asset Deal oder Share Deal bei Immobilientransaktionen, Regionaltreffen der ADI Alumni, Juni 2010
Geheimhaltungsvereinbarungen: Zahnlose Tiger? Fallstricke und effektive Rechtsverfolgung, Mandantenseminar, November 2009

Education

Diploma in Real Estate Economies (ADI)
Executive MBA Mergers & Acquisitions (EMBA)
Trainee lawyer in Mainz, including placements at a major law firm in Frankfurt and a commercial law firm in Colombo (Sri Lanka)
PhD; thesis on accounting law
Law studies in Mannheim, Alicante and Mainz

Practice Areas

Real Estate & Public Real estate transactions and financing Legal asset management Mergers & Acquisitions Climate Change, EEG and the Environment Corporate / M&A

Insights

Global Reach

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