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We have investigated the MeV behaviour of the \gray blazars 3C~454.3 and CTA102 by analyzing all COMPTEL observations of this sky region during thecomplete CGRO mission. Both sources are detected by COMPTEL at the upperCOMPTEL energies; although their flux estimates may be uncertain by possibleminor contribution of nearby unidentified EGRET \gray sources. While CTA 102was only detected at energies above 10 MeV during the early mission, 3C~454.3is most significantly detected in the COMPTEL 3-10 MeV band in the sum of alldata. Time-resolved analyses indicate a weak (near COMPTEL threshold) butlikely steady 3-10 MeV emission over years, being independent of the observedtime variability at energies above 100 MeV as observed by EGRET. Thisenergy-dependent variability behaviour suggests different emission mechanismsat work at the two bands. Putting the COMPTEL fluxes in multifrequencyperspective (radio to \grays), reveals for both sources the typical two-humpblazar spectra, with a low-energy maximum around the IR and a high-energymaximum at MeV energies. The latter one dominates the energy output across thewhole electro-magnetic spectrum. The results of our analyses are discussed inthe framework of current blazar modeling.

COMPTEL observations of the γ-ray blazars 3C 454.3 and CTA 102 during the CGRO mission