NEW YORK (AP) -- Under Armour Inc. wants to protect its "I Will" catchphrase.
The athletic clothing maker, based in Baltimore, has sued Nike Inc., claiming that its rival has infringed upon its trademarks by using variations of the phrase in marketing campaigns.
Under Armour says that since late last year, Nike has used phrases like "I will protect my home court." Under Amour says such use of "I will" is "likely to cause confusion, mistake, and deception."
Under Amour says that it has been using the "I will" phrase on hundreds of products and on packaging since 1998.
A Nike spokeswoman declined to comment.
The suit was filed Thursday in federal court in Baltimore.