At the same time, Yahoo! has appointed IDS head of interactivity Mark Connolly to the newly-created role of head of commercial development.
Wood left the role in May to become commercial director of Emap Advertising in Scotland, while Lewis had spent five years at AOL as head of agency sales.
Before that, Lewis worked for magazine publishing houses NMC, IPC and Haymarket. He is expected to utilise his experience and contacts to help agencies form strong relationships with the portal.
In the new role of head of commercial development, Connolly will be responsible for developing Yahoo!'s strategy and approach towards the client and the traditional planning agencies.
Connolly and his team will focus on educating potential and existing clients about Yahoo!'s offerings, freeing the agency team to focus on day-to-day campaign development, trading and management.
As head of interactivity, Connolly had responsibility for the digital TV sales group's interactive strategy. Previous to his time at IDS, Connolly worked at GMTV and Sky.
Blake Chandlee, commercial director for Yahoo! UK & Ireland, said: "These appointments highlight Yahoo!'s commitment to attracting the best available business leaders, from within and outside of the digital industry."