July 6 : Broadcom said on Monday it has agreed to expand its partnership with Apple through 2031 to develop and supply a range of custom chips, sending the shares of the chipmaker up nearly 4 per cent in premarket trading.Broadcom has been a supplying key components to Apple for a very long time, including custom radio frequency chips used in iPhones, Wi-Fi and Bluetooth connectivity chips and other networking semiconductors.Apple is one of Broadcom's largest customers. The iPhone maker accounts for about 20 per cent of its annual revenue, according to analysts, making it a critical contributor to the chipmaker's business.The extended partnership reinforces Apple's strategy of locking in long-term supply agreements with key chipmakers to bolster the resilience of its supply chain. In 2023,