  A three-component Ginzburg-Landau theory for a triplet pairing is developed
to understand the observed multiple phases in a new superconductor UTe$_2$
under pressure. Near the critical pressure $P_{\rm cr}$=0.2GPa where all
components are perfectly degenerate the three successive superconducting
transitions are predicted to occur. The $p$-wave pairing symmetry realized in
UTe$_2$ is characterized by non-unitarity and chirality with point nodes, thus
time reversal symmetry spontaneously broken.
