McLennan has been poached from rival agency the Cordiant Communications-owned George Patterson Bates Australia, where he was managing director on a national basis. He had been at the agency for 17 years and was being groomed for the CEO role.
He joins Y&R Australia as speculation mounts that STW Communications, partly owned by WPP, could take over Y&R following STW's buyout of 49% of J Walter Thompson, also owned by WPP, in the region.
Reports in the Australian trade press have suggested that Y&R chairman Peter Steigrad has scaled back his regional duties to focus more closely on Y&R locally.
Since joining George Patterson, McLennan has worked in every area of the agency. In 1994, he took on the international client services director role at Bates Hong Kong. Two years later, he relocated to its Sydney office, where he was named group account director and ran the Optus Communications account, the largest account held by a single agency in Australia.
McLennan was promoted to managing director of George Patterson Bates Melbourne in 1998 when he was 32, the youngest person to take the role in the agency's history.
Mike Dolan, chairman and CEO of Y&R, said: "As we build the next generation of Young & Rubicam leaders, Hamish is a wonderful addition to our team."
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