Collins Russian Dictionary 2nd Edition © HarperCollins Publishers 2000, 1997:
merchant [ˈməːtʃənt] n (trader) торго́вец* купе́ц*(ИСТ)
timber/wine merchant торго́вец*ле́сом/вино́м
* is used to mark translations which have irregular inflections. The Russian-English side of the dictionary gives inflectional information.