I doubt they use a single supplier Worldwide and I would imagine the supplier(s) change(s) every few years due to quoted price.
This suggests there may be several suppliers, if Fram only supply Diesel filters for Transits;
16/04/2018
Sogefi, the automotive component company of the CIR Group is the OE supplier of the new diesel fuel filter for Ford Transit 2.0l engine range. At the beginning of April, Sogefi has introduced the aftermarket version FramŽ C12148