The invention relates to a novel antibody capable of binding specifically to the human c-Met receptor and/or capable of specifically inhibiting the tyrosine kinase activity of said receptor both in a ligand-dependent and in a ligand-independent manner, with an improved antagonistic activity, said antibody comprising a modified hinge region.The invention also relates to a composition comprising such an antibody antagonist to c-Met and its use as a medicament for treating cancer.