Qualcomm warned that its cellular modem shipments could fall up to 40% year over year in the fourth quarter as the slowdown in China's massive smartphone market and the pivot from 4G to 5G technology create headwinds for the world's largest supplier of chips used in smartphones. The company said the slowdown is largely due to Huawei's market share gains in China after the United States slapped it with the supply ban in May. The San Diego, California-based company last week blamed its weaker-than-feared sales and profit forecast for the current quarter on a slowing smartphone market and headwinds in China, the world's largest handset market. Qualcomm forecast sales in the range $4.3 billion to $5.1 billion in the fiscal fourth quarter of 2019, falling short of analyst estimates of $5.7 billion. The outlook represents a 12% to 26% decline in sales year over year.