Upper panel: Transverse momentum spectra of primary charged particles in INEL $pp$ collisions at $\sqrt{s}=900 $GeV ($|\eta|< 0.8$), normalized to the total number of INEL events $N_{\rm evt}$, for three different event multiplicities together with the modified Hagedorn fits (Eq.1) described in the text. The fits are performed in the range $0.15 < p_T < 4$ GeV/$c$ and extrapolated to $p_T=0$. The error bars indicate the statistical and systematic errors added in quadrature. Lower panel: Ratios of the $p_T$ spectra in different multiplicity ranges to the inclusive $p_T$ spectrum in INEL events.