What you need to know:

• Former CIO for GroupM AUNZ, Seb Rennie, is returning to take over the role he left in 2018
• Rennie has been heading investment for GroupM Canada
• He starts here in June, replacing Nicola Lewis
• Lewis has returned to the UK as global Chief Growth Officer for GroupM's addressable TV unit, Finecast

GroupM Canada's Seb Rennie is returning to Australia after three years, taking over the Chief Investment Officer (CIO) role he had previously held in this market.

Rennie moved to Canada in 2018, taking over as CIO for the business.

His tenure in Canada included the roll out of GroupM’s addressable TV business Finecast and Out of Home business Kinetic.

Back in Australia, Rennie will oversee the GroupM investment and partnerships function, taking over from Nicola Lewis, promoted last October to Global Chief Growth Officer of Finecast.

Rennie will start in June.

In his last stint as CIO for GroupM AUNZ, he managed close to $3bn of media spend. 

"I’m eager to get back to Australia and join the team to help enable the ongoing evolution of investment across GroupM’s agencies and products," Rennie said.

The past 12 months has seen GroupM here undergo several leadership shake-ups, including the departure of Lewis, CEO Mark Lollback and digital boss Venessa Hunt.

Both roles are yet to be replaced; an announcement on Hunt's replacement is understood to be imminent.

Earlier this week the media investment business also appointed MediaCom CEO Willie Pang to the newly created role of Managing Director, GroupM Services, which links the group's agencies to WPP's global transformation team.

"Seb is well-known and well-respected in the Australian media marketplace and perfectly placed to take on this high-profile role at the forefront of driving industry change, best practice and business growth," GroupM APAC CEO Ashutosh Srivastava said.