State-controlled NTPC has frozen expansion of its gas-based projects due to non-availability of the fuel, according to a company official. The move comes against the backdrop of the power ministry advising power producers not to plan any gas-based projects till 2015-16 on account of gas shortage. "There is no gas. So, we have to halt the expansion of our gas-based projects at Kayamkulam, Ramagundam, Kawas and Gandhar," an NTPC official said.