  We present the results of high-quality XMM-NEWTON observations of a ULX in
the galaxy NGC 4190. The detection of spectral cutoff in NGC 4190 ULX1 spectra
rules out the interpretation of the ULX to be in a standard low/hard canonical
accretion state. We report that the high quality EPIC spectra can be better
described by broad thermal component, such as a slim disk. In addition we found
long term spectral and flux variability in the source using several XMM-NEWTON
and Swift data. A clear anti-correlation between flux and power-law photon
index is found which further confirms the unusual spectral state evolution of
the ULX. Spectral properties of the ULX suggest that the source is in a
broadened disk state with luminosities ($\approx (3-10) \times 10^{39}$ ergs
s$^{-1}$) falling in the ultraluminous regime. The positive
Luminosity-temperature relation further suggests that the multi color disk
model follows the $L \propto T^4$ relation which is expected for a black body
disk emission from a constant area and the slim disk model seems to favour $L
\propto T^2$ relation consistent with an advection dominated disk emission .
From the broadened disk like spectral feature at such luminosity, we estimated
the upper limit of the mass of the central compact object from the inner disk
radius and found that the ULX hosts a stellar mass black hole.
