A regional television news service by commercial operator WIN Television is being cut in the south-east and Riverland of South Australia.
Staff received letters on Monday telling them their positions were redundant and the news broadcast had ended, effective immediately.
WIN told staff the cuts were due to significant pressure to reduce costs.
Media Entertainment and Arts Alliance secretary, Angelique Ivanica, said she understood 10 editorial positions had been cut.
She said it was very sad day when regions were harshly affected.
"We're use to seeing a reduction in staff or some changes here or there or, in print for example a reduction in hours more recently in the last year, but when you actually have complete closure that leaves a massive gap, not only for the local residents in terms of local news coverage but also where are the staff going to go," she said.
The TV bulletin was produced and read out of the Channel Nine newsroom in Adelaide, which is also part of WIN.
It is understood the company will look for alternative positions for staff willing to consider relocating.
The WIN Television website said the company broadcast in 27 markets across Australia, including Adelaide and Perth.
Its head office is in Wollongong in New South Wales.
News Limited cuts News Limited has confirmed up to 30 production-related jobs could be affected as part of a restructuring of The Advertiser newspaper in Adelaide.
Affected staff were notified last Friday that jobs would be lost and some people might be redeployed.
A union said workers who left could expect their full entitlements.
The changes are expected to take effect by the middle of March.