  We study localization properties of electronic states in one-dimensional
lattices with nearest-neighbour interaction. Both the site energies and the
hopping amplitudes are supposed to be of arbitrary form. A few cases are
considered in details. We discuss first the case in which both the diagonal
potential and the fluctuating part of the hopping amplitudes are small. In this
case we derive a general analytical expression for the localization length,
which depends on the pair correlators of the diagonal and off-diagonal matrix
elements. The second case we investigate is that of strong uncorrelated
disorder, for which approximate analytical estimates are given and compared
with numerical data. Finally, we study the model with short-range correlations
which constitutes an extension with off-diagonal disorder of the random dimer
model.
