A multi-million dollar contract has been awarded to a company owned by the Dunedin City Council.

Delta has just signed a $40m deal to maintain electricity and fibre optic networks around Nelson.

It's a five-year contract renewal with Network Tasman, which Delta has supplied services to since 2011.

The Dunedin-based company employs 54 staff in and around Nelson.

Delta also manages the Aurora Energy network in Dunedin and Central Otago.

It's part of the council's commercial enterprise Dunedin City Holdings Limited.