The formalism of nonlinear realizations is used to construct a theory with 1/2 partial breaking of global supersymmetry with the N = (1, 0), d = 6 abelian vector multiplet as a Goldstone superfield. Much like the case of the N = 2, d = 4 Born-Infeld theory, proper irreducibility conditions of the multiplet are selected by the invariance with respect to the external automorphisms of the Poincaré superalgebra. They are found in the lowest nontrivial order in the auxiliary field. The fermionic contributions to the Bianchi identity are restored by assuming its covariance with respect to broken supersymmetry. The invariance of the action with respect to unbroken supersymmetry is checked in the lowest order in the fermionic fields. The supersymmetry preserving reduction of the d = 6 action to four dimensions is performed, resulting in the N = 4, d = 4 Born-Infeld theory. As expected, the reduced action enjoys U(1) self-duality.