Haribo, best known for its fruity gummy bear sweets, and one of its employees have been ordered to pay about €2.4 million, the federal cartel office said in a written statement.
Staff from the company regularly met up with officials from three other sweet producers in 2006 and 2007 to informally exchange details on talks with retailers on discounts.
Cartel office head Andreas Mundt said in the statement that such behaviour impaired competition even if it was not a question of "hardcore arrangements about prices, branches, customers or quotas".
Apart from Haribo, the office only named the German subsidiary of chocolate maker Mars, which had alerted authorities and was thus not fined, it said.
An inquiry is still underway into the two other sweet manufacturers, it said, adding that Haribo's cooperation in clearing up the affair had been taken into account.