Syntheo, the joint construction venture between Service Stream and Lend Lease, will hand back the remainder of its NBN rollout activities in the Northern Territory.
The company will continue contracted rollout works for NBN Co in Western Australia and South Australia.
Service Stream has been contacted for comment.
An NBN Co spokeswoman said it would "take over the design and construction of the fibre rollout in the Northern Territory."
"Details will be announced in the coming days," the spokeswoman said.
After entering a trading halt earlier this week, Service Stream this morning informed shareholders of its decision.
Service Stream said it expected to incur a one-time $3 million charge associated with Syntheo's exit from the Northern Territory NBN works.
Last month NBN Co blamed Syntheo for having to downgrade its forecasts for premises passed with fibre.
CEO Mike Quigley told a Senate Estimates hearing that last year’s forecast of 300,000 passed premises had been revised down to 286,000 due to a range of unspecified issues.
Syntheo holds two contracts with NBN Co: a two-year, $174 million contract covering builds in Western Australia, and a two-year, $141 million contract for parts of South Australia and the Northern Territory.
Syntheo joins Silcar, Transfield and Visionstream as one of four construction partners for the National Broadband Network.
More to come