Germany's Deutsche Börse says it will appeal a ruling by the Higher District German Court which states that it cannot charge Commerzbank licensing fees for using the name of its "DAX30" index.
The ruling followed a decision by a German regional court earlier this month which sided with Commerzbank by saying that the exchange could not charge licensing fees for the use of the DAX30 name.
The bank had used the DAX name in connection with some finance products and paid the fees until Deutsche Börse raised them last year. Commerzbank took the matter to court and lost the first trial but won an appeal at the Higher District Court in February.
In a stement the German exchange says: "We are still convinced of our legal position, that asking licence fees for a commercial use of our indices as underlyings for financial products is justified."
Deutsche Börse says it is a widely accepted practice to change fees for use of indices' names if they are used to support financial products.
It says the DAX index is a service product with commercial properties and argues that it should claim "reasonable compensation for the calculation, evaluation, adjustment and maintenance of our indices".