Wavelength conversion capability has been shown to significantly improve the blocking performance of all-optical networks. In order to transport payloads that may be of different bit-rates and modulation formats, a transparent wavelength conversion method is desirable. Recently, parametric wavelength converters, that are capable of multi-channel wavelength conversion for heterogeneous optical services, have been experimentally demonstrated for optical circuits. In this letter, we analyse the performance of an asynchronous optical packet-switch (OPS) architecture that exploits such devices. A sensitivity analysis of the number of converters, as a function of the main switch design parameters, demonstrate a significant reduction in the number of converters when compared with architectures employing single- channel wavelength conversion.