May 24 (Reuters) - Signatories of an United Nations-convened climate alliance will meet on Thursday to discuss next steps after some of its biggest members exited the group, Bloomberg News reported on Wednesday, citing a person familiar with the matter.

The Net Zero Insurance Alliance (NZIA) has been hit by a wave of defections recently. Swiss Re, Munich Re , Zurich Insurance and Hannover Re have walked out of the group.

In the U.S., which is a key market for many insurers, several Republican lawmakers and attorneys general have attacked companies for factoring in environmental, social and governance (ESG) concerns in corporate decision-making.

The United Nations Environment Programme, which is the convener of NZIA, did not immediately respond to a Reuters request for comment on the meeting.

(Reporting by Niket Nishant in Bengaluru)