Manufacturers that build Apple's iPhone and iPad are being drawn in to an escalating dispute between the tech giant and the chipmaker Qualcomm.
Qualcomm slashed its profit expectations Friday by as much as a third after saying that Apple is refusing to pay royalties on technology used in the iPhone.
US mobile chip giant Qualcomm is to refund BlackBerry $814.9 million in royalties overpaid by the Canadian company, according to a tentative arbitration award announced on Wednesday.
Qualcomm has moved on the offensive in its legal battle with Apple with a countersuit claiming the iPhone maker breached agreements and encouraged regulatory attacks worldwide on the US computer chipmaker.
Apple on Wednesday took its legal war with Qualcomm to China, filing lawsuits there accusing the chip-making giant of illegally wielding monopoly power.
Apple on Friday sued Qualcomm, accusing the California chipmaker of abusing its market power to demand unfair royalties, echoing charges filed days earlier by US antitrust regulators.
Mobile chip giant Qualcomm was hit Tuesday with a US antitrust suit alleging it abused its dominant position in the market for processors used in cell phones and other devices.
South Korea's antitrust regulator slapped a 1.03 trillion won ($865 million) fine on Qualcomm Inc. Wednesday for allegedly violating competition laws.
US chip maker Qualcomm on Tuesday said it will not split in two despite pressure by an activist investment fund.
The European Union's anti-trust watchdog says it suspects that Qualcomm illegally made exclusivity payments to a major customer and sold chipsets below cost to force a competitor out of the market.