A method and system to extract gas from a gas turbine having at least one gas extraction mechanism placed at the turbine section that extracts exhaust gas directly from the turbine stages through the turbine casing, providing a first exhaust gas path that extends from the turbine section through the exhaust section to the exhaust gas outlet, and a second exhaust gas path for extracted exhaust gas extending directly from the turbine stages inside the turbine casing to a duct outside of the turbine casing. The gas extraction system and method can be applied to a cogeneration system.