Third-quarter sales for St. Petersburg-based HSN were $798.9 million, up 3 percent from a year earlier. The TV, online and brick-and-mortar retailer reported Wednesday that net sales for its HSN division were unchanged at $538.6 million, but its Cornerstone division grew 8 percent to $260.3 million. Digital sales were up 7 percent for HSN and 10 percent for Cornerstone in the period ended Sept. 30. Average prices fell 5 percent for HSN and went up 13 percent for Cornerstone. Acquired by HSN in 2005, the Cornerstone division is made up of home and apparel lifestyle brands including Frontgate, Ballard Designs and Chasing Fireflies. The division operates websites for the brands, distributes more than 300 million catalogs a year and has 11 retail stores. HSN also announced that it is raising its quarterly dividend by 39 percent to 25 cents. Gross profit increased 1 percent to $288.6 million.