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Two {\it ASCA} observations were made of two ultra-luminous compact X-raysources (ULXs), Source 1 and Source 2, in the spiral galaxy IC 342. In the 1993observation, Source 2 showed a 0.5--10 keV luminosity of $6 \times 10^{39}$ergs s$^{-1}$ (assuming a distance of 4.0 Mpc), and a hard power-law spectrumof photon index $\sim 1.4$. As already reported, Source 1 was $\sim 3$ timesbrighter on that occasion, and exhibited a soft spectrum represented by amulti-color disk model of inner-disk temperature $ \sim 1.8$ keV. The secondobservation made in February 2000 revealed that Source 1 had made a transitioninto a hard spectral state, while Source 2 into a soft spectral state. The ULXsare therefore inferred to exhibit two distinct spectral states, and sometimesmake transitions between them. These results significantly reinforce thescenario which describes ULXs as mass-accreting black holes.Comment: 11 pages, 3 figures; acceoted for ApJ

Discovery of Spectral Transitions from Two Ultraluminous Compact X-Ray Sources in IC 342