The division of operations, which has not been previously reported, comes as many US universities have halted research partnerships with Huawei in reaction to US government allegations that the company poses a national security threat.

Many universities are also rethinking their partnerships with other Chinese firms.

Huawei is among the world’s largest telecommunications equipment manufacturers.

The US Commerce Department in May placed the firm on its “entity list” of organisations that pose security risks. The US Justice Department earlier filed charges against the firm alleging theft of trade secrets and other crimes.

Futurewei is Huawei’s US-based research and development arm. The firm employs hundreds of people at offices in Silicon Valley and the greater Seattle, Chicago and Dallas areas, according to its workers’ LinkedIn pages.

Futurewei has filed more than 2,100 patents in areas such as telecommunications, 5G cellular networks and video and camera technologies, according to data from the United States Patent and Trademark Office.

Until now, Futurewei’s operations had been largely indistinguishable from Huawei, the Futurewei employee said.

Futurewei had no separate brand or even a website, the employee said, and its staff often identified themselves as Huawei employees.

Both companies have conducted a wide range of research partnerships and grant programmes with US universities.

Last year, 26 members of Congress sent a letter to Education Secretary Betsy DeVos, warning that Huawei’s partnerships with at least 50 US universities “may pose a significant threat to national security”.

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The fear is that Huawei is using university partnerships to scoop up research in areas such as artificial intelligence, telecommunications and robotics, which could be used in hacking or spying operations or to give Chinese companies an edge over US competitors.

Some universities are struggling with whether they can continue partnerships with Futurewei – which is not on the government’s entity list – even as they suspend funding and research arrangements with Huawei.

The University of California-Berkeley, for instance, is allowing researchers to keep working with Futurewei after suspending all funding and information exchanges with Huawei in May, according to guidance to faculty from Berkeley research chief Randy Katz.

Berkeley also suspended funding from Futurewei but continued to allow Futurewei employees to take part in research reviews under certain restrictions, Katz wrote to faculty.

Berkeley staff and students now can work only with Futurewei employees who are US citizens or legal permanent residents and who agree in writing not to share certain sensitive information with Huawei.

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Companies on the entity list are banned from buying parts and components from American firms without US government approval.

Most universities had also consulted the list when making decisions on grants or partnerships, said Tobin Smith, of the Association of American Universities.

Katz said he issued his guidance on Futurewei out of an “abundance of caution” to ensure researchers did not break laws that prevented sharing sensitive US technology with entity-listed companies.

After consulting the Commerce Department, Berkeley determined that Futurewei was not covered by the same restrictions as Huawei, Katz wrote to faculty.

“Nevertheless, the US government may take other actions against Futurewei,” he wrote.

The Commerce Department could not legally place Futurewei on the entity list because it was a US company, the agency said in a statement.

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Commerce spokesman Ari Schaffer did not answer questions on whether and how the agency regulates university research partnerships with entity-list companies or their US subsidiaries.

There was nothing illegal about colleges taking grant money or conducting research with such companies, said Erick Robinson, head of the China practice at law firm Dunlap, Bennett & Ludwig.

What was prohibited, he said, was any transfer of “essential confidential technology” to Huawei by any person or organisation.

Prosecutors also charged the company with stealing robotic technology from T-Mobile US. The company pleaded not guilty in both cases.

The crackdown on Huawei comes amid an escalating US-China trade war, in which the transfer of US technology and intellectual property to Chinese companies has been a point of contention.

In addition to Berkeley, the list of universities that have partnered with Huawei or Futurewei includes Stanford, Princeton and Columbia universities, the Massachusetts Institute of Technology, the University of Michigan and the University of Texas at Austin.

Congressman Jim Banks, an Indiana Republican who signed the letter warning about Huawei’s university partnerships, said any move to separate the operations of Futurewei and Huawei would not resolve those concerns.

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“Futurewei is Huawei,” Banks said.

Banks is proposing an amendment to the National Defence Authorisation Act that would restrict federal funding to universities working with companies deemed a security threat.

UC Berkeley had received nearly US$8 million from the two firms in the past two years, said university spokesman Dan Mogoluf.

Katz, Berkeley’s research chief, said the school would reconsider its moratorium on taking money from Futurewei if the University of California’s office of the president gives its blessing.

The office, which oversees 10 public universities including Berkeley, said in a statement that it wanted to balance security concerns with maintaining an “open academic environment” for international scholars.

At Stanford, dean of research Kathryn Moler said the university “paused” new funding agreements from Huawei and Futurewei in December but had continued working with the firms under existing arrangements.

Moler did not answer questions about whether Stanford continues to accept money from the firms and declined to comment on whether it would lift its moratorium on new Futurewei funding if it separated its operations from Huawei.

Stanford computer science professor John Ousterhout said his lab was getting US$500,000 annually from Futurewei and had been in talks to boost that to US$2 million when he learned of the moratorium.

“I’m not here to defend Huawei. It’s quite possible that Huawei has done some seriously bad things,” Ousterhout said. But universities, he said, “should not be a law enforcement tool or foreign policy enforcement tool”.

Andrew Chien, a University of Chicago professor who lost Huawei funding, said the computer science community needed to “grow up” and acknowledge the kind of security risks that had long been managed by colleagues in such disciplines as physics, whose work has military applications.

“Computing has become so central and so important – and so dangerous,” he said. “We’re beyond the point where you can deny that.”