Completion of the acquisition

Impax Asset Management Group plc

Completion of the acquisition of Pax World Management LLC

London, 19 January 2018 - Impax Asset Managment Group plc ("Impax" or the "Company") is pleased to announce that, further to the Company's statement on 18 September 2017, the acquisition of Pax World Management LLC has completed following the admission to trading on AIM of the 2,665,989 Consideration Shares yesterday.

The number of ordinary shares in the Company in issue and number of voting rights will be 130,415,087. This figure may be used by shareholders as the denominator for the calculations by which they will determine whether they are required to notify their interest in, or a change to their interest in, the Company under the Financial Conduct Authority's Disclosure Guidance and Transparency Rules.

Defined terms are set out in the Company's announcement on 18 September 2017.

Ian Simm, Chief Executive of Impax commented:

"After a decade of partnership, I'm delighted that Impax and Pax are joining forces, creating an investment manager focused on the transition to a more sustainable economy."

"With assets under management of £11.3 billion (US$15.3 billion)1, and over 130 staff based in the UK, US and Hong Kong, the combined group is well positioned to offer a broad range of investment strategies to a global client base."

LEI number: 213800AJDNW4S2B7E680

Enquiries:

Ian Simm Tel: + 44 (0) 20 3912 3000 (switchboard)

Chief Executive

Impax Asset Management Group plc

www.impaxam.com

Anne Gilding Tel: +44 (0) 20 3912 3000 (switchboard)

Head of Brand & Communications Tel: +44 (0) 20 3912 3126 (direct)

Impax Asset Management Group plc Tel: +44 (0) 7881 249612 (mobile)

www.impaxam.com Email: a.gilding@impaxam.com

Guy Wiehahn Tel: +44 (0) 20 7418 8893Nominated AdviserPeel Hunt LLP

1Assets under management and advice as of 31 December 2017

Issued in the UK by Impax Asset Management Group plc, whose shares are quoted on the Alternative Investment Market of the London Stock Exchange. Impax Asset Management Group plc is registered in England & Wales, number 03262305. Assets under Management and Advice relate to Impax Asset Management Limited, Impax Asset Management (AIFM) Limited and Impax Asset Management LLC (formerly known as Pax World Management LLC). Impax Asset Management Limited and Impax Asset Management (AIFM) Limited are are authorised and regulated by the Financial Conduct Authority and are wholly owned subsidiaries of Impax Asset Management Group plc. Please note that the information provided and links from it should not be relied upon for investment purposes. For further information please visit www.impaxam.com.