We prove that the pointwise product of two holomorphic functions of the upper half-plane, one in the Hardy space H-1,H-, the other one in its dual, belongs to a Hardy-type space. Conversely, every holomorphic function in this space can be written as such a product. This generalizes a previous characterization in the context of the unit disc. (C) 2014 Published by Elsevier Masson SAS on behalf of Academie des sciences.