The measure for output slowed to 51.3 from 52.0 in December, while the employment index fell to 47.8 from 49, flashing a warning signal that companies are cutting jobs.
The U.S. dollar weakened slightly Thursday, adding 1 cent per ounce to gains in spot silver, while cutting declines in spot gold by 60 cents, according to the widely-watched Kitco Gold Index.