MasTec is a leading infrastructure construction company. It engages in the engineering, building, installation, maintenance & upgrade of energy, communication & utility and other infrastructure. Its Communications unit performs engineering, construction & maintenance of communications infrastructure mainly related to wireless & wireline communications & install-to-the-home. Oil & Gas unit performs engineering, construction & maintenance services on oil & natural gas pipelines & processing facilities for the energy & utilities industries. Electrical Transmission unit primarily serves the energy & utility industries through the engineering, construction & maintenance of electrical transmission lines & substations. Clean Energy & Infrastructure unit primarily serves the energy & utility end-markets & other end-markets through the installation & construction of conventional & renewable power plants, related electrical transmission infrastructure, ethanol facilities & various types of industrial infrastructure.