Cornwall is using £53.5m of EU funding to help finance the project, while BT is adding a further £78.5m.
Under the project half the population in the county will be given up to 100Mbits/sec fibre-to-the-premises (FTTP) lines, with 35 percent given the slower fibre-to-the-cabinet (FTTC), which tops out at 40Mbits/sec.
The rest, which is around 10 percent will get their broadband via satellite or wireless.
The project will benefit tens of thousands of local businesses, create 4,000 new local jobs and protect a further 2,000, BT said.
However not everyone is pleased about the situation. The deal has only gone through after companies complained to the European Courts that the deal was unfair.
Vtesse Networks previously claimed that BT’s regulated Openreach division did not provide Vtesse with the same access to its network on the same terms and conditions that it offered other BT divisions.
The decision is still under appeal.