(FORTUNE Magazine) -- Small companies have grown less optimistic about their prospects recently, according to the latest NAM/FORTUNE Manufacturing Index. In the second quarter, 85% of small and medium-sized manufacturing companies (those that employ fewer than 1,000 workers) responding to our survey were optimistic about their business prospects for the next 12 months; that was down from 91% in each of the past two quarters. Among large firms, 90% of respondents were upbeat, matching the figure from the previous quarter.

Large firms expect their sales to rise by 4.5% over the next 12 months. While that is a healthy pace, it is a measurable slowdown from the 5.1% expectation recorded in the first quarter. For small firms, expected 12-month sales growth is 4.6%, also a decline from last quarter.

Large survey respondents said they would be able to increase their prices by 1.9% over the next 12 months, a slight reduction from last quarter's expectations. Small firms expect to raise prices a faster 2.4%, a slight rise from the previous survey. All in all, the results of the most recent survey suggest that the manufacturing expansion remains on track but will shift into a lower gear in the year ahead.