UK-based chip designer ARM has told staff it must suspend business with Huawei, according to internal documents obtained by the BBC.

ARM instructed employees to halt “all active contracts, support entitlements, and any were pending engagements” with Huawei and its subsidiaries to comply with a recent US trade clampdown.

ARM’s designs form the basis of most mobile device processors worldwide.

In a company memo, it said its designs contained “US origin technology”.

As a consequence, it believes it is affected by the Trump administration’s ban.

One analyst described the move, if it became long-term, as an “insurmountable” blow to Huawei’s business.

He said it would greatly affect the firm’s ability to develop its own chips, many of which are currently built with ARM’s underlying technology, for which it pays a licence.

Cambridge-headquartered ARM had been described as the UK’s largest tech firm until its takeover by a Japanese fund. It employs 6,000 workers and lists eight offices in the US.

In a statement, it said it was “complying with all of the latest regulations set forth by the US government”, but declined to comment further