Apple said iPhone sales grew at the slowest pace since its introduction in 2007 and forecast revenue declining in the current quarter, its first such drop since 2003

Apple’s iPhone sales are flatlining, the tech company said, announcing a sharp slowdown in sales growth for its top-selling mobile device.

Apple Inc. said iPhone sales grew at the slowest pace since its introduction in 2007 and forecast that revenue in the current quarter will decline for the first time in 13 years, signaling an end to its recent period of hyper growth.

The company sold 74.8m of its flagship devices in the final three months of 2015, below analysts’ expectations. In the same period in 2014 the company sold 74.46m iPhones, meaning sales were essentially flat.

Sales of the iPhone account for about two-thirds of Apple’s revenues, which worries some investors. “Apple is a one-product company,” declared Berenberg’s Adnaand Ahmad last year, when the German bank downgraded the company’s stock to “sell”.

Shares in Apple closed at $93.44, their lowest level since mid-2014, after a warning by Tim Cook that iPhone sales would see their first year-on-year decline in the March quarter, amid what the Apple chief described as “extreme conditions” in the global economy.

IPhone sales boomed last year after the introduction of larger-screen models in late 2014, but Apple’s newest iPhones incorporate fewer noticeable changes and haven’t ignited as much enthusiasm among consumers.

Apple also said its results suffered from the effects of the strong dollar and slowing global economic growth. It warned that China, its biggest overseas market, began to exhibit “signs of economic softness” this month.

“Apple has become a victim of their own success,” FBR Capital Markets analyst Daniel Ives said. “… many customers are either buying an older, cheaper iPhone 6 or waiting for the iPhone 7.”

The slowdown in mobile sales is not confined to Apple. Worldwide smartphone growth has declined to its lowest rate since 2013, according to research firm Gartner, but signs that consumers may be tiring of new iterations of iPhones could have a profound impact on Apple and the wider US stock market.