Apple is extending an agreement to get modem semiconductors from Qualcomm for three more years, a sign that its ambitious effort to design the chips in-house is taking longer than expected. From a report: The new pact will cover “smartphone launches in 2024, 2025 and 2026,” Qualcomm said in a statement Monday. The companies’ agreement had been set to end this year, and the latest iPhone — due on Tuesday — was expected to be one of the last to rely on the Qualcomm modem chip. Instead, Qualcomm will maintain its lucrative position within Apple’s supply chain. The iPhone maker is Qualcomm’s largest customer — accounting for nearly a quarter of revenue, according to data compiled by Bloomberg. And their relationship helps validate Qualcomm’s claim to having the best smartphone modem, a critical component that allows devices to connect to the internet and make calls. Starting with the iPhone 12 generation, the chip has supported speedier 5G networks.