The rate of employment in Wales fell from 75% to 73.9% between July and September, suggesting 25,000 fewer people were in work than in the previous three months.
In comparison the UK rate of employment fell very slightly to 76%.
However, the Welsh rate remains at a relatively high level historically.
The rate of unemployment in Wales - people looking for work but not in work - fell slightly to 3.8%, the same as the UK rate.
The number of working age people not in employment in Wales because they are not available for work - due to sickness, early retirement, caring for someone or being a student - has risen compared with April to June.
The figures for July to September suggested there were 24,000 more "economically inactive" people than in the previous quarter, putting the rate at 23.1%.
The north-east of England had the highest unemployment rate of all the UK nations and regions at 5.9%, while the highest rate of employment was in the south west of England, which includes Bristol, at 81%.