CoreWeave has refuted claims that its key client, Microsoft (MSFT.US), has terminated its partnership.

The Financial Times quoted sources as saying that microsoft (MSFT.US) had walked away from part of its deal with cloud provider CoreWeave due to delivery issues and missed deadlines. The report noted that the US tech giant had retained several ongoing contracts with CoreWeave, which remained a key partner. A CoreWeave spokesperson denied the report: "We are proud of our relationships with our clients and have no cancellations or breaches of commitments. Any contrary statements are false and misleading. CoreWeave has been delivering large-scale high-performance AI infrastructure, earning the trust of world-leading AI labs and enterprises." CoreWeave provides Microsoft with computing power for its data centers, which Microsoft uses to expand its AI models such as OpenAI's ChatGPT. The report said the partnership was worth billions of dollars for CoreWeave. nvidia (NVDA.US)-backed CoreWeave is preparing for a $4bn IPO, with a valuation of more than $35bn. In its IPO filing on March 3, CoreWeave said its largest customer in 2023 and 2024 was Microsoft, accounting for 35 per cent and 62 per cent of its revenue respectively. The filing noted: "Microsoft's needs, Microsoft's ability or willingness to perform under our contracts, or any negative changes to laws or regulations applicable to Microsoft or its operations, or any changes to our broader strategic relationship with Microsoft, could have a material adverse effect on our business, operating results, financial condition and future prospects." The report also said Microsoft had agreed to invest more than $10bn in CoreWeave services under five contracts until 2030. On Tuesday, CoreWeave announced it would acquire the AI development platform Weights&Biases.