A former board director at Hill & Knowlton, Miller will start at Green Issues on 26 November. He takes the role of MD at the 35-strong Reading-based firm.
Miller's brief is to ‘consolidate and continue the growth of Green Issues' as it seeks to fend off competition from its main rival PPS Group.
Meanwhile, former APCO UK director Nick Sutcliffe has resurfaced at PPS Group. He takes the role of director at PPS, reporting to company MD Stephen Byfield.