Statistics Canada says manufacturing sales fell 1.0 per cent in January, with the decline led by the motor vehicle, aerospace and primary metal industries.
Economists had expected a drop of 0.8 per cent, according to Thomson Reuters.
Sales for January totalled $54.9 billion as 14 of the 21 industries moved lower.
The drop came as sales of motor vehicles fell 8.0 per cent to $4.9 billion, following two consecutive monthly increases.
Meanwhile, production in the aerospace product and parts industry fell 9.5 per cent to $1.6 billion, while the primary metal industry dropped 2.8 per cent to $4.1 billion.
Overall manufacturing sales in volume terms declined 1.1 per cent.
The Canadian Press