§ Section 37c (1) sentence 1 KartG standardises a fault-based liability.
Pursuant to § 37c (1) sentence 1 KartG, the violation of antitrust law can be committed intentionally or negligently without different liability consequences. Pursuant to § 37d (1) KartG, compensation for loss or damage shall include loss of profit in any form of infringement and, pursuant to (2), interest regardless of the form of fault.
Fault is the personal reproachability of the unlawful conduct. A person acts culpably if he commits a conduct which he should have avoided and could also have avoided. A distinction is made between intent and negligence. A perpetrator acts intentionally if he is aware of the illegality, foresees the harmful success and approves his occurrence. Negligence is the disregard of due diligence.
Details can be found in the book Michael BRAND, Schadenersatz im Kartellrecht, starting on page 206.