Broadband wholesaler Griffin has been selected by BT to trial its 40Mb fibre-to-the-cabinet (FTTC) network.
Beginning in July, tests will be conducted on the high-speed internet infrastructure using exchanges in Cardiff and London.
This is not the first time Griffin and BT have collaborated, with the wholesaler being the first customer for the telecoms group's 21st Century Network.
Chief Technology Officer of Griffin Adrian Sunderland gave little indication as to when the FTTC technology will be available commercially.
He commented: "Being first to market for our partners is less important than knowing that products work first time every time and are fixed quickly when they go wrong."
Mr Sunderland went on to say that the company's policy is "to trial and test with our suppliers as early as possible" to ensure new products arrive on the market promptly and without loss of quality.
The fastest consumer broadband connection currently on offer is Virgin Media's 50Mb service, while telecoms regulator Ofcom earlier this year revealed that the UK's average internet speed was 3.6Mb.