I think I've tracked it down
. I came across similar looking vintage basketweave bowls (slightly varying in shape or with added flowers), mostly for sale in the USA which were described as 'The Walter Hatches' or printed as such on the pieces. It appears that this refers to Walter Hatches Inc. who were importers of majolica/porcelain accessories from Italy, and that these bowls were handmade exclusively for this company, but the actual pottery in Italy remains unknown to me.
After a little bit more googling I came across an article in the "Bronxville Review Press and Reporter dated 1st August 1968, p.9." reporting on the death of a Mrs. Helen Walter Hatch in Bronxville who helped form "Walter Hatches" importers of decorative accessories from Italy. It goes on to state that the Italian Government was so pleased with her creations that they awarded her an honorary degree for advanced marketing relations between the U.S.A. and Italy. I've been unable to find anything more recent about the company.