Abundant resources and low prices make natural gas very attractive as petrochemical feedstock and increase the interest to its oxidative conversion to basic petrochemicals. The paper presents results of gas-phase oxidative conversion of light C-2-C-5 alkanes diluted by nitrogen, helium or methane ([CnH2n+2](0) <= 5%) at low oxygen [O-2](0)/[CnH2n+2](0) = 0.2-1, atmospheric pressure and temperatures 500-750 degrees C. Even significantly diluted, light alkanes display a chain-branching behavior at oxidation with a sharp transition trough a self-ignition limit. Oxygen significantly increases conversion and decreases reaction time, especially at intermediate temperatures below that of thermal cracking. The nature of diluting gas significantly influences on the process. (C) 2013 Elsevier B.V. All rights reserved.