US antitrust division pauses cooperation with Canadian government

Cooperation had spanned price-fixing probes and cross-border merger reviews

The US Justice Department’s antitrust division was instructed this week to halt all cooperation with the Canadian government, according to emails reviewed by The Wall Street Journal. In a Wednesday email with the subject line “Pause on Canada,” Lynda Marshall, chief of the division’s international section, ordered officials to stop case cooperation and policy engagement with Canadian authorities.

The directive halts work that has spanned joint price-fixing investigations and merger reviews for more than two decades. Antitrust officials told the Journal the order has little precedent, even as the division continues cooperating with competition authorities in countries with less friendly US relations.

Marshall provided no reason for the order in her email but said she would “circle back if the guidance changes.” On Friday, section chiefs in the division received a separate email asking them to compile lists detailing areas of cooperation with Canada by the end of the day.

US and Canadian antitrust authorities have multiple cooperation agreements in place and have worked together since the 2000s on major investigations, including probes of price-fixing in the auto parts and air cargo industries. The two sides have also coordinated on merger investigations affecting both countries, including in technology and aerospace.

The Justice Department and the White House did not immediately respond to requests for comment. Representatives for Canadian Prime Minister Mark Carney and Competition Bureau Canada also did not immediately respond.

The directive comes amid an intensifying trade dispute. The Trump administration has imposed 50% tariffs on $20 billion of Canadian goods, prompting Carney to retaliate with similar tariffs on a range of US products. Talks between the two countries broke down late last month.

The trade tensions have produced other symbolic escalations. Last week, Trump signed an executive order directing federal agencies to refer to Lake Ontario as “Lake America,” declaring that Canada “has been ripping us off for a long time on trade, very sadly.” Earlier this week, Carney criticized the taunting of Canada by US officials, saying it was not constructive toward resolving outstanding trade issues.

The antitrust cooperation pause adds a new front to the dispute. While tariffs target goods crossing the border, antitrust cooperation operates through information-sharing agreements, joint investigations, and coordinated merger reviews. The immediate scope of the impact on pending cross-border cases was not clear Friday.