Tristram Mallett

Tris Mallett’s practice focuses on corporate litigation, class action defence and securities enforcement. He frequently advises clients on contested merger transactions; take-over bid litigation; shareholder dissent and appraisal litigation and shareholder derivative claims; securities misrepresentation, fraud and insider trading matters; prosecutions undertaken by regulatory authorities and industry organizations; and related internal investigations.

Tris also defends class action claims usually in the securities, competition/anti-trust or product liability areas. These class action defence engagements are often multi-jurisdictional and cross-border in nature requiring strategic coordination with counsel in other jurisdictions including most frequently the US and Europe. Tris has acted in proceedings before various courts in Alberta, Ontario and B.C.; federal and appellate courts; and before a variety of administrative and regulatory tribunals as well as in various arbitration and mediation settings.

Representative Work

  • The Central Group Alberta Ltd.

    The Central Group Alberta Ltd. in the acquisition of Central Fund of Canada Limited by Sprott Inc.

  • Smoothwater Capital Corporation

    Smoothwater Capital Corporation in challenging proposed business combination between Alberta Oilsands Inc. and Marquee Energy Ltd.

  • Canadian Oil Sands Limited

    Canadian Oil Sands Limited in its agreement to support Suncor Energy Inc.’s amended offer valued at $6.6 billion

  • Facebook, Inc.

    The BC Court of Appeal stayed a privacy class action in Douez v. Facebook, Inc. by enforcing a forum selection clause in favour of the courts of California. In a narrow 4-3 judgment, the SCC overturned the decision.

  • Chemtrade Electrochem trial win in litigation arising from the failed business combination transaction between Canexus and Superior Plus in which each transacting party claimed a termination fee from the other following termination of the deal
  • TransAlta Corporation in proceedings before securities regulators challenging strategic partnership between TransAlta and an affiliate of Brookfield
  • Representing a group of convertible debenture holders of Perpetual Energy Inc. challenging dilutive rights offering and conversion of debentures, before the Alberta Securities Commission
  • Smoothwater Capital Corporation, an activist investor fund and a significant shareholder in Alberta Oilsands Inc., in challenging business combination transaction by plan of arrangement between Marquee Energy and Alberta Oilsands. The matter resolved itself through a settlement involving representation by Smoothwater on the Board of the combined entity and other terms.
  • Former CEO of TSX and NYSE listed issuer in Canadian and U.S. securities class action and U.S. and Canadian securities regulatory investigation, following restatement of annual financial statements
  • Defending BP plc in a proposed securities class action commenced in Alberta arising from the 2010 Deepwater Horizon explosion and subsequent Gulf of Mexico oil spill
  • Defending Facebook, Inc. in multiple proposed securities and privacy class actions in Ontario, Saskatchewan, British Columbia and Quebec
  • Groupon Inc. in a proposed class proceeding in Alberta alleging Groupon’s vochers violate consumer protection legislation
  • Securities dealers in defence of class action and institutional investor claims for misrepresentation in connection with public offerings of and trading in securities
  • Issuers, corporate officers and directors and securities industry participants in internal or regulatory investigations, and in prosecutions by securities regulatory authorities
  • Foreign state-owned international energy company in defence of proposed investor class action alleging insider trading and conspiracy
  • Defending Elpida Memory, a major international manufacturer of DRAM chips, in proposed class actions filed in Ontario, Quebec and B.C. alleging price-fixing in the manufacturing and distribution of DRAM chips
  • Defending a proposed class action against computer printer manufacturer Epson under provincial consumer protection laws for alleged misstatements about the capabilities of certain computer printer cartridges
  • Defending Imperial Tobacco in health care cost recovery actions filed in various provinces in Western Canada
  • Defending Merrill Lynch Canada in a proposed class action alleging mismanagement of client accounts
  • Defending a consumer product manufacturer in a proposed class action under British Columbia consumer protection laws and federal Competition Act alleging misrepresentations about the effectiveness of an over the counter medication
  • Defending pharmaceutical companies multi-jurisdictional consumer class actions
  • Defending a major airline in defence of class action proceedings in Ontario, Quebec and B.C. alleging price-fixing in the air cargo industry
  • Representing PetroKazakhstan in a long running dispute with Russian energy giant, Lukoil, concerning their joint ownership of energy assets in Kazakhstan
  • TransAlta Corporation with respect to its defence of the first contested enforcement proceeding brought by the Market Surveillance Administrator (MSA) alleging market manipulation and  improper trading in Alberta’s electricity market

Latest Insights

  • Blog Nov 10, 2022

    Clawing it back: SEC adopts listing standards to prevent executives from benefiting from misstatements in financial statements

    New rules adopted by the United States Securities and Exchange Commission introduce clawback requirements in cases where corporate executives benefit ...

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    Clawing it back: SEC adopts listing standards to prevent executives from benefiting from misstatements in financial statements
  • Osler Update Mar 1, 2022

    Supreme Court of British Columbia denies certification in Facebook privacy class action

    The Supreme Court of British Columbia dismissed an application for class certification, finding a “fatal flaw” in the plaintiffs’ evidence.

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    Supreme Court of British Columbia denies certification in Facebook privacy class action
  • Blog Mar 23, 2021

    Market Manipulation: Alberta Securities Commission clamps down on pump and dump scheme

    The ASC concluded the control person of Kilimanjaro Capital Ltd. (“Kilimanjaro”), Ashmit Patel, engaged in, among other things, market man...

    Read more
  • Blog Dec 23, 2020

    Alberta Court of Appeal upholds pre-certification stays of duplicative class proceedings

    On November 27, 2020, the Alberta Court of Appeal issued its decision in Ravvin v Canada Bread Company, Limited, and upheld a stay of two pro...

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    Alberta Court of Appeal upholds pre-certification stays of duplicative class proceedings
View all Insights

Awards and Recognition

  • Chambers Canada: Canada’s Leading Lawyers for Business: Recognized in Litigation: General Commercial (Alberta)
  • Chambers Global: The World’s Leading Business Lawyers: Recognized in Dispute Resolution (Alberta)
  • The Canadian Legal Lexpert Directory: Recognized in Class Actions; Litigation – Corporate Commercial
  • Best Lawyers in Canada: Recognized in Alternative Dispute Resolution, Class Action Litigation, Corporate and Commercial Litigation, Director and Officer Liability Practice
  • Who’s Who Legal: Recognized in Commercial Litigation; Canada – Commercial Litigation
  • Benchmark Litigation Canada: Recognized in Dispute Resolution; Securities; Commercial; Class Action (Litigation Star)

Media Mentions

  • Osler News Sep 25, 2023

    22 Osler lawyers recognized in Lexpert Special Edition: Energy 2023

    Osler is proud to announce that 22 of our lawyers are featured in the Lexpert Special Edition: Energy 2023, recognizing leading lawyers in the oil and...

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  • Osler News Jan 27, 2020

    29 Osler lawyers recognized in Benchmark Litigation 2020

    Osler is proud to announce that 29 of our litigation lawyers appear in Benchmark Litigation’s 2020 issue of Benchmark Canada, their annual publication...

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  • Osler News Apr 17, 2018

    25 Osler lawyers recognized in Benchmark Litigation 2018

    Osler is proud to announce that 25 of its lawyers appear in Benchmark Litigation’s 2018 issue of Benchmark Canada, their annual publication recognizin...

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  • Osler News Feb 27, 2017

    Benchmark Canada recognizes Osler’s Class Action expertise

    Benchmark Canada recently presented its 2017 awards at a gala ceremony in Toronto. We are proud to announce Osler partner Maureen Killoran Q.C. won En...

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Speaking and Writing

Published Work





  • Queen’s University, LL.B.
  • University of Guelph, B.A.


  • English

Professional Affiliations

  • Alberta and Ontario Law Societies
  • Canadian Bar Association