His main responsibilities will be to oversee the expansion of Arc in the EMEA region. Edwards takes over from John Quarrey, who leaves this month to launch a start-up.
Originally hailing from Wales, Edwards has worked in Australia since 1992, when he became the managing director of the marketing and CRM company Cartwright Williams.
When the company was acquired by iLeo, Burnett's diversified services network, he ran its Sydney and Melbourne offices until he took over at Leo Burnett Sydney.
Edwards said: "The Arc job is bound to be different from running a creative agency but I've been working in marketing services since 1986.
"Also, because the Australian advertising market is so small, and the country so big, the agencies are much more dynamic in their marketing strategies, so marketing services was a big part of my job."
Lansberg was made the chief executive of Arc in August following the departure of the previous chief executive, Nick Brien. He will work directly with Tom Bernadin, the chairman and chief executive of Leo Burnett Worldwide.
"As we go into 2006, it is our first full year as a global marketing services network, which means we can become much more repeatable and offer multinational clients much better innovation, accountability and best practice globally," Lansberg said.
"Andrew brings a wealth of direct marketing experience and operational and commercial acumen, and is perfect for this position. He's returning to his UK and European roots and will be a terrific leader for the region."