I also want to mention the completion of the acquisition of several product lines from Ashlands for our emulsions business. I'm very impressed with the new product improvements we've made in this segment and this acquisition helps us continue to advance the value of the business.
As we end the quarter, Moody's Investor Services and Standard and Poor’s rating services, both raised our outlook to positive. Balancing growth objectives with debt reduction and cash distribution in a way that move us to investment grade is important to me and to the Celanese leadership team.
For the quarter, I'm pleased to report net sales $1.63 billion, an increase of 3% over the prior year period and 1% over the fourth quarter. Diluted EPS from continuing operations came in at $1.15 per share, that an increase of $0.28 per share, approximately 32% over 2011 and it's an increase of $0.54 per share and approximately 89% over the fourth quarter. Adjusted earnings per share, which excludes these tax credits and other charges and adjustments, were $0.72 per share. These earnings are down $0.24 per share from the first quarter of 2011 and up $0.14 per share or $0.24 sequentially.
Our year-over-year earnings were impacted by weakness in the acetyl chain that is a reflection of soft demand in China and Europe, which ultimately led to over supply in Asia outside of China. Demand prices and margin were all impacted as a result. We saw similar softness in some advanced interim market segments driven by weak automobile builds in Europe, which is classically a very strong segment for Celanese. Weakness in the industrial electronics sectors also were beyond our expectations.In addition to these economic impacts that I mentioned, we continue to see strong raw material inflation trends. They keep pushing the need to drop pricing. In 2011, we saw raw material cost increase $280 million year-over-year and we expect raw materials to rise another $100 million to $110 million this year. Some of this inflation pinched our margins this quarter and while I believe we are taking steps to overcome these costs, it nonetheless represents a challenge for us. Read the rest of this transcript for free on seekingalpha.com