Germany’s competition watchdog has claimed retail giant Edeka “crossed a line” in its dealings with suppliers in the wake of its acquisition of Tengelmann’s Plus stores in 2009.

After Edeka acquired the Plus outlets, it “demanded special conditions” from 500 suppliers across its business that constituted an “abuse” of its position, the Bundeskartellamt said.

In its initial report of its findings, the competition watchdog claimed Edeka had demanded “better purchase conditions” that had been granted to Plus be introduced across its entire business. Edeka also wanted longer payment periods that had been agreed with Plus in some cases.

The watchdog also claimed suppliers were asked to pay items including “synergy bonus”, “partnership compensation” or “bonus for product range expansion”.

A spokesperson for the regulator, which first raided Edeka’s offices over the claims in 2009, will not fine the retailer but will seek to lay down which practices were unlawful.

The Bundeskartellamt has given Edeka until 20 September to comment before issuing its final ruling.

An Edeka spokesperson said: “We don’t comment on this matter due to current proceedings.”