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 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.
ARM is the foundation of Huawei’s smartphone chip designs, so this is an insurmountable obstacle for Huawei,” said Geoff Blaber, from CCS Insight.
"That said, with an abundance of companies in Huawei’s supply chain already having taken action to comply with the US order, Huawei’s ability to operate was already severely affected.