Rumsby took responsibility for the Sydney office of Weber Shandwick as general manager in November 2002.
The promotion comes ahead of the network gearing up to expand its presence within the Australian market.
Andrew Pirie, president of Weber Shandwick in Asia-Pacific, hinted at another office, confirming that the agency was investigating various strategies to re-enter the Melbourne market in conjunction with "other geographic opportunities".
"We fundamentally see enormous growth opportunities in the Sydney market and in the national market out of Sydney, with some focus in other markets as well," Pirie said.
"We are looking at whether we should have some resources placed on the ground in some of these other markets. The most obvious one of those would be Melbourne."
During Rumsby's tenure, Weber Shandwick expanded its presence in Sydney into corporate affairs, consumer marketing and technology and launched a healthcare practice.
The agency also picked up a string of industry awards, including three of the six honours received by Weber Shandwick at the recent PR Week Asia awards in Hong Kong.
This represents a turnaround of the agency's fortunes after a difficult period three years ago resulting in the closure of its Melbourne headquarters.
"We've really refocused and reshaped the whole business around our headquarters in Sydney and Ian has been instrumental is driving that business forward," said Pirie.
The Australian operations currently contributes about 10 per cent to Weber Shandwick's revenue in the Asia-Pacific region and has become a profitable operation.
"Going back three years - which was the last time there was some figures published about the size of the business in Australia - Weber Shandwick had a substantial business in terms of size, but it made very little money," noted Pirie.
"Whereas now, from a revenue point of view, it is somewhat smaller, but it is a lot more profitable, so we've got a lot more robust and sensible business model."
