How to intergrate ERP data (MM) with SRM?

Hi experts,

we have one requirement in SRM support project. Currently we are working in e-procurement. Now Client has implemented ERP also.. Now they are asking to integrate both.

Requirement is like this.---

When any user creates PO with some item details that has been save in some custom table with ref.no.in ERP. Now he wants to go for bidding for some line items in the PO. So now for that we need to display that PO details in the e-procurement application in SRM system.

what we can use now? RFCs?

SO could you please guide me how to get data from ERP and show it in SRM?

Thanks & regards,

Ramana