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The water vapor line broadening and shift in the ν 1 + ν 2 + ν 3 band induced by helium pressure were measured using a Bruker IFS 125HR FTIR spectrometer. The measurements were performed at room temperature at a spectral resolution of 0.01 cm−1 and in a wide He pressure range. The shifting coefficients δ are mainly positive, in contrast to the line center shift induced by other mono-atomic gases. Calculations of the coefficients γ and δ were performed in the framework of the semi-classical method. The influence of the rotational dependence of the isotropic intermolecular potential and accidental resonances in the H2O molecule on the shifting coefficients is discussed. Calculated values of line profile parameters are in a good agreement with observed parameters. [ABSTRACT FROM PUBLISHER]