NBN Co has signed a signed a billion-dollar, four-year contract with a consortium of six partners for construction work in the Telstra hybrid-fibre coaxial (HFC) footprint.

Lend Lease, Broadspectrum, Fulton Hogan, Downer, ISGM and BSA will tackle the construction of the NBN in Telstra HFC areas, which span around 3.5 million premises.

NBN Co expects to have completed construction to 900,000 premises within the footprint by next August.

NBN Co renegotiated its $11 billion definitive agreements with Telstra in late 2014 to include the telco's HFC network. In April this year, the network builder gave Telstra an extra $1.6 billion to help design and manage the HFC network.

That deal means Telstra will manage the six new construction partners in consultation with NBN Co. The network builder will take over the HFC network management once the build is complete.

NBN Co declined to detail the total cost of the new construction deal. The contract is understood to be worth several hundred million in the first year alone.

The work will include things like network upgrades and remediation, new lead-ins to premises, in-building cabling, and infill.

“With this process we have ensured the most appropriate delivery partners are doing the work. They have enormous experience in construction in the telecommunications industry which will help us roll it out faster," NBN Co chief network engineering officer Peter Ryan said.

NBN Co is similarly progressively taking over ownership of Optus' HFC network - which spans around 400,000 premises - but that infrastructure is not included as part of this latest deal. The network builder is still in discussions with Optus about the build of its HFC network.

NBN Co last month launched its HFC product on the Optus network in Redcliffe.

It has promised wholesale speeds of up to 100Mbps down and 40Mbps up.