ANZ statistics for newspapers and internet sites show decline of 2.9 per cent for September.
Declines in job advertisements suggest the unemployment rate could creep higher, ANZ says.
ANZ's total job ads series, which counts vacancies advertised in seven daily newspapers and the internet sites Seek and Trade Me, fell 2.9 per cent last month, seasonally adjusted, to its lowest level since April.
Auckland recorded a 3.6 per cent fall in total job ads, on top of a 2 per cent fall in August, but Canterbury rose 1.9 per cent.
ANZ's composite series, which weights newspaper and internet ads so as to give a better indicator of unemployment ahead, fell 4 per cent. "This continues to suggest the unemployment rate will rise towards 7 per cent [from 6.8 per cent now] over the next six months," ANZ economist Sharon Zollner said.
The Ministry of Business, Innovation and Employment's Jobs Online report, which monitors internet job ads only, recorded a 5.4 per cent drop in vacancies for skilled workers last month, compared with August and seasonally adjusted.
Compared with September last year skilled job ads were up 3.8 per cent, driven by a rise of 24 per cent in Canterbury and 17 per cent in the rest of the South Island.
Auckland was flat.
The largest increases were for construction and engineering workers (up 20.5 per cent over the year) and healthcare professionals (up 16.9 per cent).
"Although there has been some variation month to month, the trend series shows that skilled vacancies have been generally increasing since late 2011," the ministry said.
At 6.8 per cent New Zealand's unemployment rate only just makes the better half of the OECD rankings and compares badly with Australia's 5.1 per cent. But the statisticians count people as unemployed only if they are actively looking for work; otherwise they are counted as jobless but not in the labour force.
The employment rate, by contrast, measures the proportion of the population aged between 15 and 64 who are employed. At 72.6 per cent New Zealand has the seventh highest OECD employment rate and is slightly ahead of Australia on 72.5 per cent.By Brian Fallow Email Brian