Northland's employment rate - the percentage of people employed in the working-age population - also dropped, down 1.2 per cent to 54.6 per cent for the period.
Mr Hetherington said many part-time workers were struggling with limited hours.
"There are a lot of staff in retail that are screaming out for hours. That's quite a big issue with the major firms."
Nationally, the unemployment rate dropped to 6.9 per cent in the three months to December. That was down from a 13-year high of 7.3 per cent in the September quarter.
However the number of working age people in employment has also fallen with 23,000 fewer Kiwis in jobs.
"We're seeing fewer people working and looking for work, and more people outside the labour force," Diane Ramsay of Statistics NZ said.
"More younger people are solely in study and more older people are entering retirement."
The employment rate fell 0.8 per cent for the December quarter, to 62.6 per cent.
A breakdown showed the fall was due to a 6 per cent decline in part-time employment.
Full-time employment rose slightly (0.4 per cent).
Westpac economists called the survey an "oddball assessment" of the labour market.
"Our assessment of the labour market has not really changed - it is still weak, but we do not believe that it has suddenly gotten sharply better or worse."
Year-on-year figures showed the total number of Kiwi jobs fell 1.4 per cent in the 12 months to December. This was led by a 19 per cent plunge in self-employment, which has been falling from a peak in December 2011. APNZ
