Graham Partners has sold portfolio company Mitten to Ply Gem Industries (NYSE: PGEM). Mitten is a Canadian manufacturer and distributor of vinyl siding, vinyl siding accessories and other exterior building products. Acquired by Graham in 2011, the company increased EBITDA over 65% during the firm's hold period. BB&T Capital Markets served as the exclusive financial advisor to Graham and Mitten in the sale. Ply Gem is majority owned by CI Capital Partners.