Delta, a Dunedin City Council subsidiary company, plans to shed up to 30 jobs in the city.
The infrastructure services company maintains electricity, telecommunications, water and road systems.
Delta employs about 650 staff from Invercargill to Nelson and made a profit of $5 million last year.
In a statement Delta chief executive Grady Cameron said the company proposes to make up to 30 employees redundant in its roading and drainage operations in Dunedin.
Mr Cameron said the company must match its resources to market demand. A final decision is expected next week.
In June this year, seven Delta employees were made redundant in Queenstown and Central Otago.
Southern Amalgamated Workers Union secretary Calvin Fisher said Delta's contracting arm had gone into other parts of the South Island, when it might have been better to focus on its home region around Dunedin.
Mr Fisher said there were also questions about its property investments and expected further job cuts if Delta does not win more contracts.
Dunedin Mayor Dave Cull said the company had no choice but to cut jobs.