In the fourth quarter, we achieved a 210 point basis -- excuse me, 210 basis point sequential improvement in our gross profit as a percent of our net sales, resulting in a gross margin percentage of 23.5%. The improvement resulted from a combination of PCB premium pricing, the overall higher mix of PCB versus E-M Solutions, the reduction in the PRC energy rationing limitations on our capacity and higher cost absorption from build ahead inventory to compensate for Chinese New Year factory shutdowns scheduled in January.
Our adjusted EBITDA was $44.1 million for the quarter or 16.4% of net sales. On adjusted EPS basis, we had $0.97 per share for the quarter. Jerry will provide more color commentary on the adjusted EBITDA and adjusted EPS in his comments.
Turning to Slide 5. I want to review our revenue performance by end markets. The automotive market continues to be the largest of our end markets, representing 40% of our fourth quarter net sales. Automotive sales increased 23% year-over-year compared to the fourth quarter last year. And while we saw a 5% decline in sales compared to the immediately preceding quarter, I want to note that our fourth quarter automotive bookings were up both sequentially and year-over-year. I think we have some momentum as we enter 2012 and customer forecasts seem to support a relatively optimistic outlook for the year.
Industrial and Instrumentation remains our second-largest end market at 23% of the fourth quarter net sales. And as a reminder, I&I is a catchall category for us and includes wind and solar energy, medical, locomotion and others. As I highlighted on our call 3 months ago, the seasonally -- seasonality of demand in this market was exaggerated by customer inventory corrections after a buying spike follow the Japanese -- following the Japanese issues in early 2011. We're seeing particular strength in demand for the wind energy product prior to the scheduled end to the domestic tax credits.Read the rest of this transcript for free on seekingalpha.com