July 8 (Reuters) - Shares in Delivery Hero slump 16% to their lowest levels since February, after the German online food takeaway firm said it may face a fine exceeding 400 million euros ($433 million) due to antitrust violations.

The company said it would "significantly" increase the corresponding provisions, which it had previously built in the amount of 186 million euros. ($1 = 0.9240 euros) (Reporting by Paolo Laudani in Gdansk; editing by Milla Nissi)