The Viro sugar factory (Croatian: Viro tvornica šećera), commonly referred to as just Viro, is a sugar refinery based in Virovitica, Croatia. The company's shares are listed on the Zagreb Stock Exchange (ZSE) and is one of the 25 companies included in its official share index CROBEX as of September 2010. The company had managed to successfully bounce back in the late 2000s and it became the biggest such refinery in Croatia, with a 37 percent market share in the local sugar refining sector as of 2007.