Microsoft has rejected an option to more than double the size of its existing agreement with Nscale to rent computing power at a Texas data center, walking away from a potential deal worth tens of billions of dollars, the Financial Times reported on Thursday, citing people familiar with the matter. The report comes weeks after Microsoft pulled out of a deal to anchor Nscale's flagship data centre project in Loughton, Essex, after power connection delays pushed its expected supply date into the 2030s. Reuters could not immediately verify the report. Microsoft and Nscale did not immediately respond to requests for comment outside business hours. Nvidia-backed Nscale filed for a US initial public offering in September, with Microsoft and Anthropic expected to be among its major customers. Reuters reported last month Nscale was in talks to sell AI computing power to Claude-maker Anthropic in a new deal that could be worth about $45 billion.