Skip to Main Content
Our Commitment to Diversity
Ayman Guirguis

Ayman Guirguis advises clients on all aspects of antitrust and competition law as well as consumer law. Ayman has a wealth of experience advising clients on merger clearance, joint ventures and on supply chain arrangements between suppliers and customers. He also has experience defending court actions by the Australian Competition & Consumer Commission (ACCC) and other market participants and advising on, setting up and implementing competition law and consumer law compliance programs.

Ayman regularly advises on, and responds to, regulatory investigations by the ACCC alleging cartel conduct (price fixing, market sharing or bid rigging), including making immunity and leniency applications, competitor interactions at Industry Associations, as well as on other anti-competitive allegations such as misuse of market power, exclusivities, including defending litigation commenced by the ACCC.

Ayman also counsels clients on the Australian Consumer Law, including advertising and sales, marketing practices as well as compliance programs and audits.

Ayman has acted for clients across a range of industries including petroleum, oil and gas, property and construction, financial services, packaging, IT, retail, including food and fast moving consumer goods (FMCG) and pharmaceutical.

Prior to joining the firm, Ayman was a partner of two national Australian firms for a period of 16 years. He was also a senior officer in both the Mergers Branch and Enforcement branches of the ACCC.

  • Listed by Who's Who Legal Thought Leaders: Competition, 2024
  • Recognised by The Legal 500 Asia Pacific as a Leading Individual for Competition and Trade in Australia, 2022-2024
  • Recognised as a Global Elite Thought Leader by Who's Who Legal in the area of Competition, 2021
  • Listed Euromoney's Expert Guide for Competition and Antitrust in Australia, 2020-2021
  • Lawyers Weekly, finalist in the Partner of the Year Awards for Competition, Trade and Regulation, 2020-2021
  • Recognised by The Legal 500 Asia Pacific as a Recommended Lawyer in Australia
    • Regulatory Compliance and Investigations, 2018-2020
    • Competition and Trade, 2015-2021
  • Recommended by Who's Who Legal (Australia) in the area of Competition, 2017-2023
  • Listed in The Best Lawyers in Australia™
    • Competition Law, 2013-2025
    • Commercial Law, 2025
  • Recommended by Who's Who Legal (Global) in the area of Competition, 2012-2023
  • Recognised by Chambers Asia-Pacific for Competition/Antitrust in Australia, 2008-2024

"I have been dealing with Ayman for more than ten years and have followed him between firms due to his deep industry knowledge and quick, commercial and pragmatic advice." and "Ayman is a pleasure to work with. He is deeply knowledgeable and incredibly practical and pragmatic." (Chambers Asia-Pacific 2024)

 "Ayman Guirguis is a stand out in this space. Ayman is attentive, highly responsive, knowledgeable, and experienced. Ayman is deeply experienced in liaising with regulators and understands what is required. Ayman’s advice is practical, honest, and succinct, all of which are critical when working to strict timeframes." (The Legal 500 Asia Pacific 2024)

"Ayman Guirguis is very knowledgeable on competition and consumer law issues. He is also very easy to work with and has a deep understanding of our business, which makes him a valuable legal partner." (The Legal 500 Asia Pacific 2023)

"Ayman is well-respected, experienced and easy to work with. You always feel like he is giving you 110% attention and effort. He is refreshingly practical and realistic rather than being overly conservative. He goes out of his way to keep in touch. As he has clients across a number of industries, he sees a breadth of issues and regulatory engagement which is insightful." (The Legal 500 Asia Pacific 2023)

"Ayman Guirguis is a long-term legal partner and advisor to our business. He has a wide breadth of knowledge and experience which is highly trusted by our team." (The Legal 500 Asia Pacific 2023)

Ayman Guirguis "is very commercial, practical, easy to work with and responsive. He also has extensive and impressive experience across a range of sectors and clients, and has his finger on the pulse in relation to competition law developments and areas of regulatory focus." (Chambers Asia-Pacific 2022)

Ayman Guirguis "always strives to understand his client’s businesses so he can provide relevant and practical advice. His advice is always well considered, detailed and with risk ratings to assist in-house counsel to make well-informed, strategic decisions with the business." (The Legal 500 Asia Pacific 2022)

Ayman Guirguis "has incredible attention to detail, and will run down every last fact or legal argument when providing advice." (The Legal 500 Asia Pacific 2022)

"Ayman Guirguis has a deep interest and understanding in his client’s businesses and industries which allows him to deliver holistic, commercially-sound legal advice that considers the broader practical implications for the business." and "Each member of the team down to associate level is highly capable and it is apparent that they have the benefit of the close mentorship of Ayman Guirguis." (The Legal 500 Asia Pacific 2021)

Ayman Guirguis is identified by sources as "someone who takes the big picture and looks for solutions, as well as providing excellent legal analysis." (Chambers Asia-Pacific 2021)

Ayman Guirguis has this "insight into the mind of the regulator" and "very thorough, practical and timely advice on how things will play out" and known for his "very affable, down-to-earth manner" and willingness for clients to "bounce ideas off him." (Chambers Asia-Pacific 2020)

Ayman Guirguis is "a highly regarded competition lawyer whose practice combines a number of sector-specific skills with broad competition expertise. A satisfied client reports: He gets to the point, is at the forefront of the industry and regulation and is always pre-empting issues for us in an unprompted way." (Chambers Asia-Pacific 2019)

Ayman Guirguis is described as "very commercial and practical." (The Legal 500 Asia Pacific 2019)

Ayman Guirguis is "well known in the market for his deep experience across all areas of Australian competition law. His dedication to his clients is also appreciated by interviewees, one of whom notes: Ayman is incredibly responsive and reliable and always makes you feel like your matter is top priority. He always goes out of his way to provide excellent service and to understand his client's business." (Chambers Asia-Pacific 2018)

Ayman Guirguis is "easy to work with and showcases a commercial approach with great breadth and depth of knowledge." (The Legal 500 Asia Pacific 2018)

  • Australian Non-Government Adviser representative of the International Competition Network, 2009-2017
  • Law Council of Australia Competition and Consumer Law Committee member
  • American Bar Association member
  • International Bar Association member
  • Association of Corporate Counsel member
  • Law Society of New South Wales member
Additional Thought Leadership Pages
Additional News & Event Pages
  • Quoted, "'Disappointing': Lawyers bemoan loss of ability to challenge ACCC's merger decisions in court", Lawyerly, April 2024
  • Mentioned, "Americold’s AU$1.7 Billion Acquisition of Agro", Global Legal Chronicle, December 2021 
  • Mentioned, "Dicker Data buys New Zealand’s ‘second-largest’ IT distributor",, August 2021
  • Mentioned, "Dye & Durham’s AU$170 Million Acquisition of GlobalX", Global Legal Chronicle, June 2021
  • Mentioned, "K&L Gates assists in GlobalX merger",, June 2021
  • Mentioned, "Swedish comms giant makes billion-dollar Aussie acquisition",, June 2021
  • Mentioned, "Visy completes landmark glass packaging acquisition",, August 2020
  • Mentioned, " ACCC greenlights pharmaceutical collaboration during COVID-19",, April 2020
Return to top of page

Email Disclaimer

We welcome your email, but please understand that if you are not already a client of K&L Gates LLP, we cannot represent you until we confirm that doing so would not create a conflict of interest and is otherwise consistent with the policies of our firm. Accordingly, please do not include any confidential information until we verify that the firm is in a position to represent you and our engagement is confirmed in a letter. Prior to that time, there is no assurance that information you send us will be maintained as confidential. Thank you for your consideration.

Accept Cancel