Telstra has secured two contracts from the national broadband network (NBN), with combined first-year revenue of about $80m.

The telecommunications group is also negotiating a third contract with NBN to cover design, engineering, procurement and construction management of the network, and the agreement is likely to be finalised in early 2016.

The new contracts, announced on Monday, include a three-year deal to fix faults on the copper network and undertake some new connections for services yet to be moved to NBN.

Telstra will also function as one of the network operations and maintenance service providers to NBN under a separate four-year contract.

The work will involve fixing faults and connecting new services on the network for fibre to the node, fibre to the premises, fibre to the basement and hybrid fibre coaxial technologies once a customer has switched to NBN.

The new contracts mean Telstra will be paid to repair the copper network it sold to NBN in a $11bn deal in 2011.

In August, it was revealed the cost of the national broadband network could blow out by $15bn.