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Mariel Dimsey

Senior Associate
Hong Kong

Mariel Dimsey
English, German
Practice Group

Mariel is an international commercial and investment arbitration specialist. She has almost 10 years’ experience acting as advisor and advocate in numerous international arbitrations covering a wide range of legal systems and industries. She also sits as arbitrator. One of Mariel's strengths is her ability to create pragmatic solutions for her clients in a competent and cost-efficient manner.

Mariel is an Australian Lawyer and received an LL.M. degree from the University of Cologne and a doctorate in law (Dr. iur.), summa cum laude, from the University of Basel, both in investment arbitration. She started her career at Hogan Lovells in Frankfurt, then worked with a leading U.S. law firm in Germany and the ICC International Court of Arbitration in Paris, before rejoining Hogan Lovells in Hong Kong.

Mariel speaks and publishes regularly on international arbitration and international commercial law topics. One of her recent publications is a Commentary on Article 4 of the UNCITRAL Transparency Rules. She has also taught international arbitration at the Universities of Bonn and Frankfurt. Her native language is English and she is fluent in German.

Representative experience

Representing a multinational chemicals company in UNCITRAL ad hoc proceedings in Frankfurt concerning a supply dispute*

Representing a Middle Eastern client in ICC proceedings in Geneva concerning an energy dispute*

Representing a German investor in an ad hoc bilateral investment treaty arbitration in Geneva, Switzerland under public international law against an Asian state.

Representing a German client in ICC proceedings in Singapore under Swiss law concerning obligations under a share purchase agreement.

Representing a Belgian client in ICC proceedings in Germany under German law in a dispute arising out of a corporate restructuring transaction*

Representing a German corporation in ICC proceedings in Switzerland under U.S. and German law arising out of an intellectual property dispute*

Representing an Italian company in CAM proceedings in Italy under Italian law arising out of an advisory dispute*

German corporation in relation to bilateral investment treaty claims against an Asian state in connection with a construction project.

Asian state on investment protection and arbitration.

German corporation on the availability of investment protection for EPC contracts.

German corporation in relation to bilateral investment treaty claims against a Middle Eastern state in connection with water utilities.

German corporation in relation to investment and contract law claims against various parties in connection with an infrastructure project in Sub-Saharan Africa.

German client in relation to enforcement of an arbitral award against a sovereign state in several jurisdictions.

Belgian client in relation to enforcement of trademark rights in several jurisdictions pursuant to findings in an arbitral award*

Danish citizen in relation to enforcement of an arbitral award in Germany*

Sole Arbitrator, ICC Rules, German situs, German substantive law, sales dispute, Bulgarian and German parties

Institution-appointed arbitrator in three-member tribunal, DIS Rules, German situs, German substantive law, supply dispute, German and Indian parties*

U.S. technology company on FCPA and UK Bribery Act compliance concerning a local subsidiary, including conducting a comprehensive internal investigation*

Assisting on achieving global antitrust clearance of a multibillion dollar, three-part transaction between two global pharmaceutical companies.*

Advising on anti-trust issues with respect to a large-scale European Commission investigation into price fixing in the automobile industry.*

*Matter handled prior to joining Hogan Lovells.

Education and admissions


  • Dr. iur., University of Basel, 2007
  • LL.M., University of Cologne, 2005
  • LL.B., University of Queensland, 2003
  • B.A., University of Queensland, 2000


  • Arbitral Women
  • Australian Centre for International Commercial Arbitration (ACICA)
  • Asia-Pacific Forum for International Arbitration (AFIA)
  • HK45
  • ICC Australia
  • Swiss Arbitration Association Young Practitioners Group (ASA Below 40)
  • German Initiative of Young Arbitrators (DIS 40)
  • Young Arbitrators Forum of the International Chamber of Commerce (ICC YAF) (Former Regional Coordinator Europe)

Bar admissions and qualifications

  • New South Wales, Australia

Court admissions

  • Supreme Court of New South Wales, Australia


"Associate to Watch"

Chambers & Partners

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