The seasonally-adjusted Purchasing Managers' Index (PMI) edged lower to 49.9 index points in January 2019, down from 50.7 in December 2018.
Despite the decline, the index remains 2 points above the average recorded in 2018, which suggests that manufacturing started the year on fairly solid footing.
The performance of the PMI's sub-components was more mixed, with many of the sub-indices declining compared with their December levels.