A German court battle has put the relationship between marketer and media agency on trial as French dairy giant Danone Groupe accuses Aegis Media of failing to pass on the full benefit of discounts gained from bulk media purchases more than five years ago.

In an attempt to resolve the dispute, the Higher Regional Court in Munich has ruled verbally that Aegis Media's Carat operation in Germany must open up its books. Aegis, unwilling to reveal sensitive market information, is awaiting the written ruling, due at the end of January, before contesting the judgment.

Essentially, the two sides are unable to agree on the extent of the transparency that was written into their media-buying contract between 2003 and 2005, and have been fighting about it for several years. Since then, Danone has conducted more than one review of its media business in Europe, including a procurement-driven global review late last year in which WPP's Mediacom won the German business. Ad Age ranks Danone as the 21st biggest global marketer with annual ad spending of more than $900 million worldwide.

To read the full story visit AdAge