Chinese tech giant Huawei on Tuesday unveiled its first smartphone equipped with a fully homegrown operating system, a key test in the firm's fight to challenge the dominance of Western juggernauts.

Huawei has fully developed its own operating system to compete with Google’s Android and Apple’s iOS, a first for a Chinese company.

SINGAPORE—Huawei Technologies plans to roll out its most advanced domestically made phone chip, people familiar with the matter said, showing how the company is able to make strides in semiconductors despite U.