BT is investing around £220m in improving broadband connectivity in Wales.
The company announced the project, which will attract £425m of investment by the end of 2015, on Thursday.
The scheme will see fibre-to-the-cabinet (FTTC) and fibre-to-the-premises (FTTP) rolled out in areas of the country where fibre would not normally be commercially viable, delivering download speeds of up to 80Mbps. The average download speed across Wales is currently 5-6Mbps, BT said.
In addition to BT's £220m contribution, the Welsh government is contributing £58m to the project and has secured £57m from Broadband Delivery UK (BDUK) and around £90m from the European Regional Development Fund (ERDF).
However, the plan still needs to be given the green light by the European Commission as it is subject to state aid and major projects approval.
While this might not normally be a problem, the EC Competition Commission recently confirmed it was looking into the BDUK funding process as only BT seemed to be winning tenders for different counties. In many cases BT and Fujitsu were the only two companies left in the running for certain areas.
If it is given the rubber stamp of approval by the Commission, BT said it would also create 50 new jobs and 100 new apprenticeships, as well as protecting 320 existing jobs.
The project, which aims to deliver fibre to non-commercially viable areas using government subsidies, is separate to BT's ongoing rollout of fibre services in commercially viable areas, which already included parts of Wales.
In addition to creating new jobs, and safeguarding existing ones, BT said the additional infrastructure investment would enable a range of services not available to lower bandwidth users and businesses.
"For local businesses, the fibre network will underpin the introduction of many new services and applications," BT said. "Big business applications driven by cloud services and datacentres will be within the reach of enterprises of all sizes, computer backup, storage and processing will be faster, and the use of high quality videoconferencing within firms and between them and their customers will become a viable possibility."
Despite the benefits of super-fast broadband Britons have been slow to sign up for the highest speed services, according to research published this week.