Qualcomm filed suit against Apple on Wednesday in a California state court, alleging the iPhone maker breached a software license contract and used proprietary code with competitor Intel.
The contract Apple allegedly broke surrounds software designed to make Qualcomm chips work with other iPhone components, Bloomberg first reported. Qualcomm believes Apple could have given Intel access to the proprietary software to help with its own chip development.
The companies' legal battles have been raging for months. It began in January with Apple accusing the semiconductor giant of overcharging for chips and withholding nearly $1 billion in contractual rebate payments. Qualcomm has also responded with a lawsuit in the US that opened an ITC probe.
An Apple or Qualcomm spokesperson wasn't immediately available for comment.
Earlier this week, it was reported Apple is designing its iPhone and iPads for next year without any components from Qualcomm. Instead, Apple will use only Intel and MediaTek to supply modem components, according to The Wall Street Journal.
Qualcomm reported in its fourth-quarter earnings on Wednesday its licensing business took a hit as a result of its ongoing legal battle with Apple and other licensees, but its core business saw solid growth.