Job advertisements fell 0.7 percent in December, the second monthly fall in a row.
However, because of a strong October, ads in the three months to December were up 2.8 percent.
The biggest contributor to the latest monthly drop was a 1.5 percent fall in internet advertising while newspaper ads rebounded strongly in December after a large fall in November.
ANZ economist Steve Edwards said monthly figures tend to be volatile but broad trends indicate a modest decline in the unemployment rate over the next two quarters.
Internet advertising continues to grow at the expense of newspaper ads.