(Reuters) – Apple Inc and its allies on Monday will kick off a jury trial against chip supplier Qualcomm Inc in San Diego, alleging that Qualcomm engaged in illegal patent licensing practices and seeking up to $27 billion in damages.

FILE PHOTO: The logo of Apple is seen at a store in Zurich, Switzerland January 3, 2019. REUTERS/Arnd Wiegmann/File Photo

Qualcomm, for its part, alleges that Apple forced its longtime business partners to quit paying some royalties and is seeking up to $15 billion.

Filed by Apple in early 2017, the lawsuit in federal court revolves around the modem chips that connect devices like the iPhone or Apple Watch to wireless data networks. Qualcomm has spent the past two years mounting a pressure campaign of smaller