After a brief introduction to spinor-helicity formalism, BCFW recursion and Grassmannian representation of tree-level on-shell amplitudes in N=4 SYM theory we present a conjecture for Grassmannian integral representation for tree-level off-shell gauge-invariant amplitudes (Wilson line form factors or reggeon amplitudes) in N=4 SYM. The corresponding Grassmannian integrals are evaluated for several explicit examples and the results are compared with the predictions of corresponding off-shell BFCW recursion.