A method for operating a gas turbine plant having a gas turbine and an electric generator driven by the gas turbine. The method includes detecting an instantaneous power of the gas turbine plant; comparing the detected instantaneous power with a power limit value; and limiting the instantaneous power when the result of the comparison is that the detected instantaneous power is equal to or greater than the power limit value. A step of detecting at least one operating parameter of the gas turbine plant and a step of determining the power limit value as a function of the at least one detected operating parameter are then implemented, wherein the at least one operating parameter of the gas turbine plant includes an ambient pressure and the power limit value is increased when the ambient pressure increases.