Tham, who joined the network in late 1999, fills a role on a par with Asia-Pacific chairman Miles Young to manage a combined market of 2.8 billion consumers in 14 countries.
"We cannot divorce the two entities of business and creativity so it is only natural that we have this type of partnership," said Tham.
O&M's move contrasts sharply with sister WPP agency J. Walter Thompson, which last month divided Asia-Pacific into four areas (Media, January 24) to empower local teams and speed up turnaround times for clients.
Young described the new structure as "ying and yang", but pointed out that the partnership was "not a recipe you could take off the shelf and apply to any organisation".
Under the new structure, Tham will be responsible for overall creative strategy, leaving Young to focus on the business side. O&M's continued drive to crack two of Asia's toughest markets - Japan and Korea, where WPP has purchased a controlling stake in LG late last year - is also seen as a key factor behind Tham's elevation, according to industry observers.
"I want to elevate the role of creativity in the company and make it known that Tham and I are the criticial people within our agency," said Young.
Tham's role will be expanded to working more closely with local market heads, particularly on big name accounts such as American Express and Coca-Cola. "My new role is to raise the creative standard, give more of a creative bite," Tham said.
Last month, O&M promoted Gary Tranter, Matt Cullen and Kevin Geeves to regional creative partners and hired Spencer Wong to the expanded role of executive creative director for Hong Kong and southern China.