  A form of mixing matrix for three active and three sterile, conventional
Majorana neutrinos is proposed. Its Majorana lefthanded part arises from the
popular bimaximal mixing matrix for three active neutrinos that works
satisfactorily in solar and atmospheric experiments if the LSND effect is
ignored. One of three sterile neutrinos, effective in the Majorana righthanded
and Dirac parts of the proposed mixing matrix, is responsible for the possible
LSND effect by inducing one of three extra neutrino mass states to exist
actively. The corresponding form of neutrino mass matrix is derived. Also, the
respective neutrino oscillation probabilities are calculated.
