Mr Green revealed that he plans to run the world's fourth-largest bank as a "double act" with chief executive Michael Geoghegan.
Speaking to the Financial Times, Mr Green explained that while he would take charge of strategy and corporate governance, as well as representing HSBC around the world, Mr Geoghegan would ensure that the strategy is delivered by leading the bank's management team.
"There is an important double act which enables the chairman to have the time to focus on the things that a chairman is responsible for and the CEO to focus with the management team on the performance of the company," he explained.
The bank's share price has been damaged in recent months following concerns over bad mortgage loans made by HSBC's US consumer finance subsidiary, Household. However, Mr Green defended Household's management and insisted that HSBC is learning from past mistakes.
Looking to eastern Europe, Mr Green said it was true that the bank had missed out on an opportunity in the region during the 1990s, but added that HSBC is now ready to capitalise on the relatively young market.
"I think in eastern Europe there are opportunities in small business, there are opportunities in consumer finance, there are opportunities in direct banking," he concluded.