We generalize Lie bialgebras and Lie bialgebroids to new objects which
we call generalized Lie bialgebras. Similar to Lie bialgebras and Lie
bialgebroids, generalized Lie bialgebras are self-dual and generate c
anonically Hamiltonian structures on their representative spaces. We s
how that for a generalized Lie bialgebra (E, (E) over bar), a pair (L-
1, L-2) of E + (E) over bar is again a generalized Lie bialgebra iff (
L-1, L2) is a Dirac structure pair. Construction of generalized Lie bi
algebras by using Poisson tensors and Hamiltonian operators are also d
iscussed in detail and an example relating to an infinite-dimensional
integrable system is given.