The private-equity firm Kohlberg, Kravis, Roberts (KKR), was famously branded “the Barbarians at the Gate” 20 years ago in a book of that name about the firm’s hostile takeover of RJR Nabisco. Now KKR is embracing un-Barbarian environmentalism, in a new partnership with the NGO Environmental Defense Fund (EDF).

Matthew hosted a fascinating panel discussion between Ken Mehlman of KKR and Gwen Ruta of EDF today at the annual conference of the Association of Management Consulting Firms. The alliance, a promising example of philanthrocapitalism, is the result of the acquisition in 2007 of a Texas-based electricity firm, TXU, by KKR and TPG, another private-equity firm. TXU wanted to build 11 new “dirty” coal-fired power stations, which EDF and other green campaigners fiercely opposed. As part of the acquisition, KKR and TPG agreed to cancel those plans, and look for greener alternatives. EDF helped convince the media that this promise was sincere.

Since then, KKR has expanded this relationship into a formal alliance that will ultimately include all the firms in its portfolio, says Mr Mehlman, who is best known for his former management role in George Bush’s re-election campaign in 2004. EDF has been one of the leaders among NGOs in its willingness to work with companies, since it helped McDonald’s introduce eco-friendlier packaging in the 1980s. To avoid conflicts of interest, it never accepts money from companies, relying instead on funding from supporters, including some big philanthropists. Earlier this year, EDF’s president, Fred Krupp, published a fine book, “Earth: The Sequel: the race to reinvent energy and stop climate change”, which is full of ideas for businesslike ways to address environmental causes.

As readers of our book would expect, the attraction of the green agenda to KKR is primarily financial, cutting costs, though Mr Mehlman says that leading firms nowadays must play a positive role in causes such as this. And not just on the environment. Although KKR has been attacked over its employment practices by the influential union, SEIU, Mr Mehlman says it is working to develop constructive, innovative solutions to labour problems (including sharing gains that result from restructuring with workers), including in partnership with former Democrat senator Dick Gephardt. Barbarians no more?