The deal will see Openreach providing additional fibre capacity and diverse routing to meet growing demand from Next Generation Data's business and government customers.
NGD customers will have access to more than 200 communications providers selling Openreach Ethernet and Optical services to the end user business markets - including options from 10Mbps up to multiple 10Gbps services.
Tim Barclay, MD, sales, marketing and customer engagement at Openreach said: "This announcement continues our major push into the UK data centre market. By bringing our open access model to the NGD data centre in Wales, we're enabling them to offer their customers a wide choice of high speed Ethernet services. We're also speeding up the provisioning of our Ethernet services by building fibre links direct to major data centres across the UK well ahead of any customer orders."
Nick Razey, CEO, Next Generation Data, said "This agreement underscores Next Generation Data's long established and highly successful relationship with BT both as a point of presence (POP) and as a strategic data centre services provider.
"We are delighted that BT is increasing its high speed fibre capacity at our world-class carrier neutral NGD Europe facility which will further extend the wide choice of high bandwidth, low latency communications available to our customers."