The legal battle between Apple and Qualcomm has turned even nastier with the US chip giant hitting back with a counterclaim against Apple’s $1bn patent licensing lawsuit. Apple filed suit against its primary modem supplier in January, accusing it of overcharging for patent royalties; withholding over $1bn which it owes the iPhone maker; and operating an “illegal scheme” to monopolize the smartphone chip market. Now Qualcomm has hurled its own accusations, claiming that Apple has mischaracterized its agreements and the performance of its chips; encouraged recent regulatory attacks on Qualcomm’s business; and interfered in the chip provider’s agreements with other licensees which produce iDevices. In its filing, Qualcomm denied “each and every allegation” made by Apple in its complaint. Another…