(Corrects story to remove incorrect reference to Hongmeng OS rollout on 1 million devices in paragraph 2 and 4 after official clarification from company)

By Diego Oré

MEXICO CITY, June 13 (Reuters) - An executive of China's Huawei, which has been banned from working with U.S. tech firms, said on Thursday that the telecoms giant is in the process of potentially launching its "Hongmeng" operating system (OS) to replace the U.S. Android OS.

Andrew Williamson, vice president of Huawei Technologies Co Ltd's public affairs and communications, said in an interview that the company will "presumably" trademark Hongmeng.

President Donald Trump's administration last month put Huawei on a blacklist that barred it from doing business with U.S. tech companies such as Alphabet Inc, whose Android OS is used in Huawei's phones.

"Huawei is in the process of potentially launching a replacement," Williamson said in Mexico City. "It's not something Huawei wants. We're very happy of being part of the Android family, but Hongmeng is being tested, mostly in China."

"Presumably we'll be trying to put trademarks," he added.

Williamson said he expected 2019 revenue growth would be almost flat at around 20%, compared with last year's expansion of 19.5%. Huawei said in March its three main business groups were likely to post double-digit growth this year.

Williamson said that if trade tensions escalate into a full-blown trade war, Hongmeng would be ready to go "in months."

Data from the U.N. World Intellectual Property Organization shows that Huawei, the world's biggest maker of telecoms network gear, has already applied to trademark Hongmeng in a number of countries.

Williamson said chipmakers knew that cutting off Huawei could have "catastrophic" consequences for their business.

"We're not specifically asking anyone to lobby for us. They're doing it by their own desire because, for many of them, Huawei is one of their major customers," he said.

Huawei has come under mounting scrutiny for over a year, led by U.S. allegations that "back doors" in its routers, switches and other gear could allow China to spy on U.S. communications.

The company has denied its products pose a security threat. (Reporting by Diego Ore in Mexico City Writing by Daina Beth Solomon Editing by Dave Graham and Leslie Adler)