Since the EU, Moldova and Turkey are contracting parties to the PEM Convention and there are bilateral FTAs between each two of them, is diagonal cumulation possible among the three parties?

Still not, as currently not all conditions are fulfilled (e.g. notice indicating the fulfilment of the necessary requirement to apply cumulation still not published in EU Official Journal). Bearing also in mind that the FTA between Moldova and Turkey unilaterally provides for cumulation with the EU, at export to the EU the cumulation with Turkey is not allowed. Neither can preferences be granted for Turkish goods imported from the EU with a proof of origin issued in the EU. While at export to Turkey the cumulation with the EU is possible e.g.to use EU materials. The last case would be the application of the cumulation provided for in the Moldova-Turkey FTA, not the PEM cumulation, which is still not applicable.