CMOS Monolithic Active Pixel Sensors (MAPS) demonstrate excellent performances in the field of charged particle tracking. A single point resolution of 1--2 mu m and a detection efficiency close to 100% were routinely observed with various MAPS designs featuring up to 10 super(6) pixels on active areas as large as 4 cm super(2)1. Those features make MAPS an interesting technology for vertex detectors in particle and heavy ion physics. In order to adapt the sensors to the high particle fluxes expected in this application, we designed a sensor with fast column parallel readout and partially depleted active volume. The latter feature was expected to increase the tolerance of the sensors to non-ionizing radiation by one order of magnitude with respect to the standard technology. This paper discusses the novel sensor and presents the results on its radiation tolerance.