This paper presents transmission system distance relaying co-ordination using detailed simulation studies of the apparent impedance loci as seen from the relaying location considering various operating conditions including fault resistance. Support vector machines (SVMs) are used as a pattern classifier for obtaining distance relay co-ordination. The scheme utilizes the apparent impedance values observed during fault as inputs. An improved performance with the use of SVMs, keeping the reach when faced with different fault conditions as well as system power flow changes are illustrated with an equivalent 246 bus system of practical Indian Southern grid. © 2008 IEEE.