We investigate the scenario of resonant thermal leptogenesis, in which the
leptonic asymmetries are generated through renormalization group corrections
induced at the leptogenesis scale. In the framework of the standard model
extended by three right-handed heavy Majorana neutrinos with masses M1 = M2 <<
M3 at some high scale, we show that the mass splitting and CP-violating effects
induced by renormalization group corrections can lead to values of the CP
asymmetries large enough for a successful leptogenesis. In this scenario, the
low-energy neutrino oscillation data can also be easily accommodated. The
possibility of having an underlying symmetry behind the degeneracy in the
right-handed neutrino mass spectrum is also discussed.Comment: 20 pages, 2 figures, final version to appear in Phys. Lett.