The novel neon complex NeBeCO3 has been prepared in a low-temperature neon matrix via codeposition of laser-evaporated beryllium atoms with O-2 + CO/Ne. Doping by the heavier noble gas atoms argon, krypton and xenon yielded the associated adducts NgBeCO(3) (Ng = Ar, Kr, Xe). The noble gas complexes have been identified via infrared spectroscopy. Quantum chemical calculations of NgBeCO(3) and NgBeO (Ng = He, Ne, Ar, Kr, Xe) using ab initio methods and density functional theory show that the Ng-BeCO3 bonds are slightly longer and weaker than the Ng-BeO bonds. The energy decomposition analysis of the Ng-Be bonds suggests that the attractive interactions come mainly from the Ng -> BeCO3 and Ng -> BeO sigma donation.