Earlier, the company registered two other names for the OS - HongMeng and Ark.
Huawei has been working on its own operating system for more than a year, and it could be launched as early as 2019.
Now, a third name - Harmony - has been added to the list. Huawei registered this trademark with the EU Office on 12 July. It is speculated that HongMeng will be used for the Chinese market, and Harmony for the rest of the world.
According to a recent comment by the head of Huawei, Ren Zhengfei, the Huawei operating system will be used not only for its smartphones, but also other types of devices, including routers, switches and onboard vehicle computers.
The US and a number of other nations have been accusing Huawei of stealing commercial information via its gadgets, and alleged that the company was working on behalf of the Chinese government.
Huawei has vehemently dismissed the allegations.
The pressure on Huawei comes against the backdrop of a trade spat between the United States and China, with the two sides exchanging several rounds of tariffs.