Apple’s profits in China fell by almost a fifth in its latest financial year, a stark reversal after operating income there more than doubled in 2015, the Financial Times reports. The figures will fuel investor concern that Apple is losing out to local rivals such as Huawei, Vivo and Oppo in what until recently has been its biggest source of growth. In its annual report for its financial year ending in September, filed on Wednesday, Apple revealed that operating income in Greater China fell 18% to $18.8bn, as revenues there dropped 17% to $48.5bn. The previous year, Apple’s operating income in the world’s largest mobile market had leapt from $11bn to $23bn as Chinese consumers flocked to buy the iPhone 6. China sales almost doubled to $58.7bn in fiscal 2015.