A new two-component relativistic pseudopotential (PP) of the energy-consistent (EC) variety, adjusted to multiconfiguration Dirac-Hartree-Fock (MCDHF) data, is presented for the superheavy element III and is applied in correlated valence ab initio calculations, with and without inclusion of spin-orbit (SO) coupling, to the determination of spectroscopic constants of the element 111 monohydride. Good agreement with a recent study by Han and Hirao [Chem. Phys. Lett. 328 (2000) 453] is found, and it is concluded that a direct two-component PP fit is superior to a previously practiced two-step (scalar-relativistic/SO) adjustment procedure. We estimate the molecular constants of element 111 monohydride to be R-c = 1.529 Angstrom. D-c = 2.83 eV and omega (c) = 2642 cm(-1).