Major tech firms are protesting against Nvidia's $40 billion acquisition of UK semiconductor firm Arm. The deal was announced back in September and is currently under review by antitrust regulators in the US, UK, European Union and China. Bloomberg reports several companies -- including Google, Microsoft and Qualcomm -- are asking for these regulators to intervene. According to the site's sources, at least one of these companies wants the deal to be stopped altogether. The concern centres around Arm's work providing semiconductors and essential chips to companies such as Apple, Amazon, Samsung, Huawei and Intel. The firm currently provides its services to all clients across the tech industry, but the likes of Microsoft and Google are concerned that the acquisition would allow Nvidia to limit supply to rivals or increase prices.