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McCarthy Tétrault LLP


7 ranked lawyersBand 1Nationwide - CanadaCanada 2022 View ranking table
chambers review
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Ranked Lawyers
chambers review
department information
Ranked Lawyers

Chambers Review

Chambers Research is conducted by 200 Research Analysts, across 200 jurisdictions and provides nearly 6,000 rankings tables. Annually we collect hundreds of thousands of responses from clients, the majority via in-depth interview. Learn more about our methodology.

What the team is known for

McCarthy Tétrault operates a dynamic and well-established competition law practice group, featuring considerable experience of investigations, transactions and disputes, as well as foreign investment. Clients appreciate the team's assistance and advocacy skill in dealings with the Competition Bureau. The law firm acts for clients on both criminal proceedings and civil matters, including cartel class actions, as well as compliance programmes. It represents a varied list of international and domestic clients, including household names in the transportation, telecommunications and entertainment sectors, such as Westjet and Hockey Canada. The group has an impressive track record handling prominent, blue-chip cross-border merger files.


"This is the best competition team in Canada," said one client, adding: "They work seamlessly together and all share very strong client advocacy skills."

"Their extraordinary depth of knowledge stands out for me," explained one impressed source, while another said: "McCarthy Tétrault has consistently provided top-shelf work in both merger reviews and litigation."

Work highlights

A team led by Jason Gudofsky and Deborah Salzberger acted for Refinitiv on its USD27 billion acquisition by the London Stock Exchange.

Notable practitioners

Casey Halladay is a respected competition lawyer with a skill set covering both merger review and regulatory enforcement. He continues to be engaged in a number of major cross-border transactions.
"Casey Halladay has specialist knowledge across all elements of deal planning, including merger control, the Investment Canada Act and the interaction between Canadian processes and other jurisdictions." "He forges his insights into strategies that effectively and efficiently achieve his client's objectives."

Deborah Salzberger provides guidance to clients on the process of investment and merger review, including navigating the Investment Canada Act. Her recent work includes several impressive mandates in financial services and construction.

Montréal-based Dominic Thérien is a respected competition law expert with expertise in major merger review and foreign investment files. He recently acted for CDPQ on its role in the acquisition of Bombardier's transportation operations by Alstom.

Donald Houston is an eminently respected member of the Canadian competition Bar, with an impressive career that has seen him represent clients in both regulatory enforcement and litigation. He also has significant experience in merger and investment review files.

Jason Gudofsky is frequently engaged to provided competition advice on a multitude of complex and high-profile cross-border transactions.
"He is simply the best Canadian competition lawyer I have worked with: he is creative, assertive and singularly client-focused." "Jason Gudofsky is very responsive and is an extraordinary subject matter expert."

Nikiforos Iatrou is an experienced litigator and antitrust lawyer with significant experience advising on abuse of dominance and misleading advertising cases. He particularly impresses for his work in the technology and e-commerce sectors.
"Nikiforos Iatrou is very responsive and incisive, and is a steady hand when interfacing with the Competition Bureau." "He did a very good job advocating on our behalf."

Oliver Borgers has cultivated a solid reputation in the Canadian competition market, with significant experience advising on all manner of transactional reviews, including acquisitions, joint ventures and strategic alliances.
"I need someone who gives me the confidence that the course I take is the right one and nothing is going to fall through the cracks - that is what I get with Oliver Borgers."

Department Information

This content is provided by McCarthy Tétrault LLP.


We are widely recognized as some of the best competition lawyers in Canada. With our unique ability to integrate exceptional expertise in both of Canada’s legal systems (civil and common law) and both of Canada’s official languages (English and French) to address any client issue, our group is entrusted to advise on some of Canada’s most significant and industry-changing competition matters.  

From our expertise in transactional matters and investigations, to litigating high-stakes competition matters, our outstanding reputation extends to the full spectrum of competition law services.

Clients turn to us to for our extensive experience in clearing complex mergers and, when necessary, our ability to litigate to get their deal through. Our clients also benefit from our robust in-house e-discovery services which means that responses to Competition Bureau information requests in merger review (or other types of competition investigations) are managed in a highly efficient and cost-effective manner.

We have acted as counsel on landmark competition cases and have been retained by the Commissioner of Competition in Tribunal proceedings. We have advised on almost all of the national and international cartel cases in Canada over the past 20 years. As well, we have a track record of success in defending competition class actions, as well as class actions in general, that is unsurpassed in Canada.


McCarthy Tétrault LLP


Suite 5300, TD Bank Tower

Toronto Dominion Centre




M5K 1E6

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Ranked Lawyers

Chambers Research is conducted by 200 Research Analysts, across 200 jurisdictions and provides nearly 6,000 rankings tables. Annually we collect hundreds of thousands of responses from clients, the majority via in-depth interview. Learn more about our methodology.

Nationwide - Canada


Casey W Halladay
Band 3
Deborah Salzberger
Band 4
Dominic Thérien
Band 5
Jason Gudofsky
Band 1
Oliver J Borgers
Band 2

Competition/Antitrust: Litigators

Donald B Houston
Senior Statespeople

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