The company's shares were down by 14.15 percent to 14.80 euros in morning trading on the Paris stock exchange that was up 0.52 percent overall.
GDF Suez chief executive Gerard Mestrallet said that the plan, announced the previous evening after markets closed, could be achieved without
The company is targeting 3.5 billion euros ($4.6 billion) in savings by 2015 and aims to reduce its debt by a third to 30 billion euros by the end of 2014.
"GDF Suez is in the process of transforming itself from a traditional European utility to a leading global actor in the energy market," said Mestrallet.
GDF Suez is the top independent electricity producer in the world and is also a leading natural gas distributer and provider of water and waste services.
The natural gas market is still regulated in France and the company estimated that it lost 185 million euros in the second half of this year due to a price cap that has since been ruled illegal.