FRANKFURT -- German printed circuit board fabricators reported sales fell 10% year-over-year in September, in part due to a shorter work month.

This September had two fewer work days than September 2011, noted ZVEI PCB and Electronic Systems, which tabulates the data. Orders fell from August but were up 17% from a year ago. Orders were down 5% compared to the 10-year average for the month.

The book-to-bill ratio for the month was 0.99. A ratio over 1.0 is considered an indicator of higher near-term orders.

Year to date sales are 10% from 2011.