(Changes source, adds details, share movement) July 21 (Reuters) - Piper Jaffray upgraded Gibraltar Industries Inc (ROCK.O: Quote, Profile, Research) to "buy" from "neutral," and said the metals manufacturer and processor is expected to report strong second-quarter results, driven by cost-reduction efforts and price increases, sending the company's shares up 19 percent.

"While broader end markets remain challenging, we believe that internal cost reductions and the successful pass through of rising steel costs provide support to our above-consensus estimates," analyst Michael Cox wrote in a note to clients.

The analyst, who raised his price target on the stock by 50 cents to $16, expects the company to earn 46 cents a share in the second quarter, 8 cents above the consensus estimate.

He said the company's stock has fallen 25 percent since the end of June, and the recent pullback creates an attractive entry point.

Operating margin is expected to improve year-on-year due to cost reductions associated with facility closures completed late last year and early this year and commodity-based price increases on steel products, Cox said.

Shares of Gibraltar jumped 18 percent to $14.72 in morning trade on Nasdaq. They had touched a high of $14.81 earlier. (Reporting by Mary Meyase in Bangalore; Editing by Deepak Kannan)