Reinsurance giant Swiss Re AG dropped out of the United Nations-convened Net-Zero Insurance Alliance on May 22, bringing to four the number of companies that have left the group in recent weeks amid antitrust concerns.

"Swiss Re has decided to withdraw from the [alliance] with immediate effect," the Zurich-based company wrote in a statement to media. "Our commitment to our sustainability strategy remains unchanged."

A spokesperson for the group said it does not comment "on the individual independent actions of its members."

Swiss Re's departure comes just days after 23 US Republican state attorneys general wrote a letter to Swiss Re and other global insurers warning that their climate collaboration may be violating state and federal antitrust laws. By teaming up with other insurance companies to meet emissions reduction targets, the companies could be engaging in an "illegal boycott, especially if the group of competitors working together has market power," the attorneys general wrote.

In Europe, regulators are taking steps to ease antitrust restrictions that could dissuade financial firms from joining or staying in climate alliances. In the US, where a GOP-led campaign against corporate environmental, social and governance investment criteria has gained traction, there is uncertainty over how antitrust laws apply to corporate climate collaboration.

In another high-profile departure, the Vanguard Group Inc. quit the Net-Zero Asset Managers Initiative in December 2022, ostensibly over similar concerns. Like Swiss Re, the bank promised to stick to its climate goals.

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