Grey previously held the account, and ran it for the Munich-based insurer out of its German office. Grey won the business in 2009, when it was estimated to be worth £60 million.
Alongside its sister WPP media agency MediaCom, Grey set up a dedicated global division – Team Allianz@Grey – to service the account.
In 2012, Grey London was separately handed the UK advertising account for Allianz. The UK account was not part of the global pitch.
Allianz launched as a UK consumer brand in 2009. It used to sell its insurance products direct to consumers through the brand Cornhill, which it acquired in 1986, and the pet insurer Petplan.
Today, Allianz reported a 10 per cent rise in revenues to €29 billion (£23 billion).