The present invention is directed to a universal channel dispersion compensating fiber (CDCF) for WDM channel compensation that provides essentially zero dispersion slope over the wide wavelength band used in state-of-the-art transmission systems. It allows compensation of a large number of channels using a single fiber design. The improved optical fiber of the invention exhibits a dispersion slope at 1550 nm: <0.02 ps/nm2-km, preferably <0.01 ps/nm2-km, and a maximum variation of dispersion per km over the S-, C-, and L- bands of preferably less than 2.0 ps. In a preferred embodiment, the index profile of these fibers comprises a simple three layer design, which includes an up-doped central core, surrounded by a down-doped trench region, further surrounded by an up-doped ring region.