Feb 07, 2013. /Lesprom Network/. The Board of Directors of Koppers Holdings Inc. declared a quarterly dividend of $0.25 per common share, payable April 8, 2013, to shareholders of record as of the close of business on February 19, 2013. The quarterly dividend amount of $0.25 represents a 4% increase over the previous quarterly dividend rate of $0.24 per share, as the company said in a press release received by Lesprom Network. Koppers, with corporate headquarters and a research center in Pittsburgh, Pennsylvania, is a global integrated producer of carbon compounds and treated wood products. Including its joint ventures, Koppers operates facilities in the United States, United Kingdom, Denmark, The Netherlands, Australia and China.