We consider the three lepton decay modes of the proton within the prot
on decay interpretation of the atmospheric neutrino anomaly. We constr
uct higher dimensional operators in the framework of the standard mode
l. The operators which allow the interesting decay modes are of dimens
ion 10 involving SU(2)L non-singlet Higgs. We show how these operators
can be comparable to the dimension 9 operators. We then present a sim
ple model which can give rise to the desired proton decay modes of the
right order of magnitude.