Ameron International Corp. reported double-digit growth for its third quarter thanks mainly to increased sales, the company said.

Ameron’s third-quarter net income of $21 million ($2.32 per share) was a 17 percent increase from $18 million ($2.02) in the same period a year earlier thanks in part to a tax benefit, the company said.

Sales for the Pasadena-based engineering firm and pipeline equipment maker jumped 18 percent to $165 million, mainly because of a surge in sales of fiberglass-composite pipe materials, the company said.

“The Fiberglass-Composite Pipe business and Hawaiian operations made major contributions to offset the water-pipe market slowdown and the soft residential housing market,” said the company’s chief executive, James Marlen.

Shares in Ameron gained 2.3 percent, or $2.33, to $102.24 in afternoon trading on the New York Stock Exchange. Shares are up 59 percent since April.