Women on Boards is the latest organisation to cut ties with the law firm, following a series of accusations which paint a culture of sexual harassment as rife within the firm.
All six of New Zealand's law schools have cut ties with Russell McVeagh as well as the NZ Schools' Debating Council.
The firm has announced it will undertake an external review in response to "serious" sexual allegations involving law students.
Dame Margaret Bazley has been appointed to head the review of incidents which took place in 2015/16.
Bazley would be assisted by a female lawyer whose appointment will be announced shortly.
Pip Greenwood, a senior partner at Russell McVeagh, said: "We recognise that the incidents of sexual harassment that have occurred at our firm have had a profound effect on the women involved and we are all truly sorry and horrified that they occurred."
Greenwood said: "We are extremely grateful to Dame Margaret for agreeing to conduct this review."
This year's Women on Boards conference is being held on May 10, 2018 at Auckland's Pullman Hotel with the theme Moving up the Ladder: Mapping your governance journey.
Nominations for the awards, which were in their third year, were open until April 6.