An ethylene homo- or copolymer composition is stabilized by suitable stabilizers conferring improved resistance against thermo-oxidative degradation, which occurs in the presence of liquid fuels comprising biodiesel, such as vegetable oil esters, in combination with oxygen. The stabilizers comprise a combination of at least two sterically hindered amine compounds or N-hydroxy- or N-oxylderivatives thereof in an amount of from 100 to 10 000 ppm. Such ethylene homo- or copolymer composition is highly suitable for articles of plastic and components for the transport and storage of liquid fuels comprising biodiesel, such as vegetable oil esters, preferably for plastic fuel tanks for automotive vehicles.