
Woodside, in turn, is replacing Tim Armstrong who is joining AOL as its new global chief executive.
The role of Mark Howe, who runs Google's UK agency sales operation, remains unchanged.
Brittin will not take up Woodside's responsibilities as head of Google's Ireland and Benelux operations, which will now be overseen by their respective country managers.
Brittin joined Google in January 2007 to run its UK direct sales. In his new role, he will now oversee Google's agency and sales operations teams. Brittin joined Google in January 2007 from Trinity Mirror where he was director of strategy and digital.
He said: "We are working hard with our UK partners and customers to help them take advantage of the online opportunity, particularly at this time".
Woodside, Google's vice-president for the UK, Ireland and Benelux regions, joined Google in 2003 and is credited with launching Google's direct sales operation in Eastern Europe and also launched its sales group in Dublin.
He will oversee Google's advertising in the US, Canada and Latin America.
Omid Kordestani, Google's senior vice-president of global sales and business development, told staff: "We believe it's now time not just to roll-out globally the best practices from the different reginal sales teams - the Americas, EMEA and Asia Pacific - but also to tailor our business strategies more closely to the different situations we face in different countries."
Woodside joined Google five-and-a-half years ago from McKinsey & Company, where he was an associate partner.