Georgia Gulf Corp., which makes a variety of building products that carry the Royal Group and recently acquired Exterior Portfolio brands, said its building products segment's operating loss more than tripled in the first quarter to $12.1 million from a $3.7 million loss in the first three months of 2010.

Sales rose 3% to $157.5 million when the company includes the Exterior Portfolio business, which become part of Georgia Gulf on Feb. 9. But excluding that acquisition's revenue, sales fell 8%.

"The increase in operating loss was primarily due to a change in the geographic sales mix and higher raw materials, conversion and selling costs," the Atlanta-based company said in its earnings announcement, issued late Wednesday. Georgia Gulf attributed the sales decline to lower sales volumes, noting that sales in 2010 were driven in part by homebuyer tax credits in the United States and Canada that expired at the end of last year's first quarter.

Both years' operating losses carried footnotes. This year's $12. million loss includes $2.4 million in acquisition deal costs and inventory purchase accounting adjustments that were offset by a $3.6 million reversal of a non-income tax reserve. Last year's $3.7 million loss includes $600,000 in restructuring costs.

"The increased costs of PVC and other raw materials is challenging margins in our building products segment," president and CEO Paul Carrico said. "North American demand continues on a very slow pace to recovery, as housing and construction markets have remained weak so far in 2011. We continue to build on the improvements we have made in this business during the last two years to take advantage of the eventual recovery in both the economy and housing."