  We performed spectroscopy of five Luminous Blue Variable (LBV) candidates and
two known LBV stars (AE And and Var A-1) in M31. We obtained the same-epoch
near-infrared (NIR) and optical spectra of these stars. The NIR spectra were
taken with Triplespec spectrograph at the 3.5-m telescope at Apache Point
Observatory, and the optical spectroscopy was done with SCORPIO focal reducer
at the 6-m BTA telescope (SAO RAS). The candidates demonstrate typical LBV
features in their spectra: broad and strong hydrogen lines, HeI, FeII, and
[FeII] lines. All our candidates show photometric variability. We develop a new
approach to the LBV parameters estimation based on the inherent property of
LBVs to change their spectral type at constant bolometric luminosity. We
compare the spectral energy distributions of the variable stars obtained in two
or more different states and estimate temperatures, reddening, radii and
luminosities of the stars using this method. Two considered candidates
(J004526.62+415006.3 and J004051.59+403303.0) have to be classified as new LBV
stars. Two more candidates are, apparently, B[e]-supergiants. The nature of one
more star (J004350.50+414611.4) is not clear. It does not show obvious LBV-like
variability and remains an LBV-candidate.
