iPhone sales are expected to shrink for the first time this year

The iPhone fueled Apple’s ascendance into the world’s most valuable company. But even iPhone sales have their limits. Apple on Tuesday reported results for its fiscal first quarter that showed iPhone sales rose less than 1 percent from a year earlier, the slowest year-over-year growth rate ever for the device, which accounts for about two-thirds of the company’s revenue. Apple also issued a sales forecast that signaled that the sluggishness would continue, with the company projecting its first revenue decline in more than a decade. The results and guidance reflect how Apple, under its chief executive, Timothy D. Cook, is grappling with becoming a maturing tech company and is now entering a period of slow growth. While Apple once delivered high double-digit revenue gains on the back of soaring sales of the iPhone and other devices, that has decelerated as the iPhone has begun saturating the market and the company has not introduced a new blockbuster device. In a conference call with analysts on Tuesday, Mr. Cook said that the slowdown at Apple was indicative of greater global economic and financial market uncertainty.