By Tommy Wilkes

LONDON (Reuters) -The remaining insurers in a United Nations-backed coalition aimed at tackling climate change are poised to loosen the alliance's membership requirements, after a recent exodus of members, according to two people familiar with the discussions. The U.N.-convened Net-Zero Insurance Alliance (NZIA) is set to remove a six-month deadline for members to publish greenhouse gas emissions targets alongside other changes to make membership less prescriptive, the sources said.

The hope is to "steady the ship" and create space for ex-members to consider returning later, they said. The NZIA has lost more than half its members including AXA, Lloyd's of London and Tokio Marine since attorneys general from 23 Republican-run U.S. states sent a May 15 letter seeking information about insurers' membership and threatening legal action.

The attorneys general said the NZIA's requirements for members to publish and meet greenhouse gas emission-reduction targets appeared to violate antitrust laws, and that the alliance's actions had pushed up insurance and other costs for consumers. Launched in 2021 to drive insurers' efforts to hit zero emissions on a net basis by 2050 in their underwriting portfolios, the NZIA is one of several industry coalitions under the Glasgow Financial Alliance for Net Zero (GFANZ) umbrella group.

The NZIA now has 12 members, down from a peak of 30. Other GFANZ alliances have also faced U.S. political pressure but have not seen many members leave.

CONCERN FROM CAMPAIGNERS The NZIA's 'target-setting protocol' published in January required insurers to publish their initial 2030 targets for reducing emissions by end-July, or within six months of joining for newer entrants, and then report their progress against the targets annually. But remaining members, among them Britain's Aviva (LON:AV), Italy's Generali (BIT:GASI) and South Korea's Shinhan Life, want to avoid insurers publishing targets simultaneously, which could invite fresh accusations of anti-competitive collaboration, the first source said, speaking on condition of anonymity because of the sensitivity of the matter.

An NZIA spokesperson declined to comment.

The potential for looser rules was met with concern by environmental campaigners, who say insurers are already doing too little to curb emissions and that aggressive collective action is needed.

"The NZIA has had very minimal requirements and expectations of membership from the start," said Peter Bosshard, coordinator of the Insure our Future campaign.

The alliance, Bosshard said, developed less stringent requirements - such as not restricting fossil fuel underwriting - than another investor coalition, the Net Zero Asset Owners Alliance, precisely to avoid accusations it was breaching anti-trust laws.

"The target-setting is the only thing left," he added. Without such requirements "the NZIA would just become another industry talking shop".

Other proposals being discussed include making the alliance a broader forum where insurance industry bodies participate in areas like target-setting best practice, the first source said.

The changes under discussion have not been finalised, the sources said, and it's not clear how the alliance would deal with insurers that drag their feet in publishing targets.

U.S. EXPOSURE

Insurers inside and outside the NZIA say they remain committed to their net-zero pledges despite the backlash in the United States.

They are convinced they are not violating antitrust rules, but companies departing the coalition were concerned about their exposure to regulatory and litigation risks, given U.S. states are the industry's primary regulator. Insurers with little U.S. exposure have also been quitting, threatening the alliance's viability.

Insurance Australia Group declined to explain its exit last month. Canada's Beneva said the U.S. political debate around environmental, social and governance (ESG) criteria was "a distraction from the actions around which the company wishes to rally".

Remaining members believe the NZIA still has a valuable role, and point to methodologies it developed for assessing and reporting on underwriting-linked emissions. France's AXA, which chaired the NZIA before quitting in May, last week published its first emissions goals for its insurance portfolio.