We consider pseudo-Dirac-type neutrinos with Majorana masses which are smaller than their Dirac ones. It is shown that there are two possible kinds of resonant neutrino oscillations for each generation, whose interplay provides an economical way to solve the puzzles of solar and atmospheric neutrinos simultaneously.

• Received 20 May 1991

DOI:https://doi.org/10.1103/PhysRevLett.67.1685