Sigma was born in 1969 as the fusion between various companies. Previously known as Yarhi S.A, it merged with other companies with the same interests, among them Cartonera S.A., Rotoflex S.A., and Industrias Gráficas Salvadoreñas S.A. Hence its name, as the Greek letter "sigma" describes an integral, which was what was being done in practice: integrating interests and integrating companies. Through the years, this vision has expanded: 13 companies and 7 sales offices in El Salvador, Guatemala, Costa Rica, Honduras, Nicaragua, Mexico, Dominican Republic and the U.S. are consolidated under one name.