  The purpose of this paper is to prove the equality between the algebraic
Iwasawa $\lambda$-invariant and the analytic Iwasawa $\lambda$-invariant for a
Hilbert cusp form of parallel weight $2$ at an ordinary prime $p$ when the
associated residual Galois representation is reducible. This is a
generalization of a result of R. Greenberg and V. Vatsal.
