The interference effects between two burning spheres have been analyzed utilizing Labowsky’s approach for problem formulation leading to the Laplace equation in a potential function and employing the finite-element method for its solution. The effect of separation on the interaction coefficient, the potential field and the dame geometry has been established. The critical spacing providing the demarcation between merged and separated flames is shown to. be a function of the stoichiometric coefficient, radius ratio, ambient oxidizer concentration and ambient temperature. Correlations between the critical nondimensional spacing and the critical interaction coefficient and the above parameters have been obtained for both equal- and unequal-sized drops. The cone criterion, originally proposed for equal drops, is extended to the case of unequal drops and the correlation between the cone half-angle and the parameters has been established.