The electron mobility in silicon-on-insulator (SOI) layers has been extracted from magnetoresistance data measured on a four concentric ring test structure, operating in pseudo-MOS configuration, using Kelvin's technique. Ohmic contacts were fabricated using a thermally evaporated erbium/silver double layer. The relative magnetoresistance versus magnetic field characteristics demonstrated classic quadratic behavior allowing for straightforward extraction of magnetoresistance mobility. The technique does not require any correction to be applied due to contact resistance or geometrical effects. The electron mobility extracted using magnetoresistance technique is discussed and compared with theoretical predictions. (C) 2010 Elsevier Ltd. All rights reserved.