Total Voting Rights

1 October 2012

Impax Asset Management Group plc ("Impax" or the "Company")

Total Voting Rights and Capital

In conformity with the FSA's Disclosure and Transparency Rules DTR 5.6.1, the Company announces that its issued share capital consists of 115,582,431 ordinary shares of 1 pence each. The Company holds 4,699,000 shares in Treasury.

Therefore, the total number of voting rights in the Company is 110,883,431 which may be used by shareholders as the denominator for the calculations by which they can determine if they are required to notify their interest in, or a change to their interest in the Company, under the Disclosure and Transparency Rules.

Enquiries:

Impax Asset Management Group plc 020 7434 1122

Ian Simm, Chief Executive

Espirito Santo Investment Bank 020 7456 9191

John Riddell

James Bromhead