Apple's newest flagship, the iPhone X, could have a shorter lifespan than expected, according to a highly regarded analyst who has reported lukewarm demand for the device, particularly in China.

In a recent research note, Ming-Chi Kuo of KGI Securities said that the iPhone X (pictured above) could reach its end of life this summer, according to AppleInsider. He predicted Apple will sell some 18 million units of the device in the first quarter of this year, adding that the phone's front-facing camera notch has hurt its appeal to Chinese consumers.

A separate report from Consumer Intelligence Research Partners (CIRP) noted that Apple's latest iPhones accounted for a smaller proportion of U.S. sales in the final quarter of 2017 than in the same period of the previous year. CIRP reported that the iPhone 8, iPhone 8 Plus, and iPhone X together represented around 61 percent of Apple's phone sales, compared to the 72 percent taken by the iPhone 7 and iPhone 7 Plus in 2016. Apple is scheduled to report its first quarter results on Feb. 1.

iPhone X Plus Could Push Out X

Apple had struggled with a number of design and supply issues ahead of the November launch of the iPhone X. The company had reportedly tried to incorporate the front-facing sensors into an all-glass display, but ended up leaving a small notch at the top to accommodate those.

The design has led some consumers to perceive that there is less usable screen space on the iPhone X than on the larger-body, notch-free iPhone 8 Plus, according to Kuo's analysis, seen by AppleInsider. The iPhone 8 and iPhone 8 Plus were both released in September.

The publication reported on Friday that Kuo predicts Apple will retire the iPhone X this summer, replacing it with an iPhone X Plus. He also predicted that Apple will launch two additional new iPhones this year, most likely in the fall.

When it was launched, the $1,000-plus iPhone X was touted by Apple as "the future of the smartphone." The device eliminates the home button and Touch ID in favor of front sensors that support facial recognition for security. It also introduces an OLED display design and a suite of new features for augmented reality applications.

Larger Screens Driving Sales

Meanwhile, a report from CIRP showed that the sales mix of iPhones in the last quarter of 2017 was markedly different from that in 2016. 9to5Mac attributed part of that to the fact that the iPhone X arrived later than usual. Apple typically releases its latest iPhones in September.

"This report estimates iPhone X made up about 20 [percent] of total iPhone sales in the 2017 holiday quarter, a very respectable portion of sales considering it didn't go on sale until November," the site reported.

Other recent iPhone models also performed well in the final quarter, according to CIRP. The iPhone 8 accounted for more than 20 percent of sales, while the iPhone 8 Plus accounted for more than 15 percent, and the iPhone 7 and iPhone 7 Plus each made up more than 10 percent.

"This means half of iPhones sold in the quarter had screen sizes larger than 4.7-inches, the largest ever share," 9to5Mac reported. "In terms of company financials, bigger-screened iPhones are also more expensive contributing to higher iPhone ASP and revenue."

In November, Apple reported slightly higher-than-expected fourth quarter revenues of $52.6 billion, a 12-percent increase over the same period in the previous year. The company also projected Q1 2018 revenues of $84 billion to $87 billion.