The service provider will bring its super-fast internet to the territory after tying up a £425 million deal with the Welsh government.
BT will provide up to 96% of homes and businesses in the country with fibre broadband by 2015 as part of what has been hailed as the biggest initiative of its kind in the UK.
The news follows an Ofcom report that found Wales to have the lowest rate of super-fast broadband coverage in Britain.
"This project will position Wales as a broadband leader and we are delighted to have signed this contract with the Welsh Government to make it happen," said BT Openreach CEO Liv Garfield.
"Wales will become one of the-best connected countries in the world and will be ahead of the chasing pack. The Welsh Government has shown great vision and we are certain that will pay off in terms of economic growth.
"The apprenticeships and work experience that we're offering will mean the roll-out of this next-generation network will inspire the next generation of workers."
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Welsh customers will have access to download speeds of 80MB/s when the roll-out has been completed, a significant increase on the five to six MB/s currently available. Businesses will benefit from speeds of up to 330MB/s.