Initially the review, which is being conducted on a market-by-market basis, will only involve roster agencies.
Wrigley's is currently conducting an audit of MediaCom, which has held its UK media account for the past four years. It is expected to invite other agencies to compete for the business later in the process.
However, Wrigley's would not confirm if the review would affect the UK market.
Gharry Eccles, the managing director, UK and Republic of Ireland, of The Wrigley Company, said: "We have a very successful relationship with our media buying and planning agency, MediaCom. Over the past four years, MediaCom has consistently provided a great service and, as such, there is no pitch taking place."
News of the European review comes four months after Wrigley's reviewed its £85 million media planning and buying in the US. It was awarded to MindShare after a pitch against Wrigley's roster shops MediaCom and OMD.