British Airways has been accused of colluding in setting prices of fuel surcharges and other levies in the provision of air freight services.
BA confirmed it received a letter of complaint from European Union regulators, alleging that it was part of a suspected air freight cartel.
The complaints were also sent to Germany's Lufthansa, Air France-KLM and Scandinavia's SAS.
The airlines have the right to respond, but if found guilty, they face fines.
The European Commission that it had sent official letters, known as statements of objection, to a number of air freight firms, concerning "violation of EU rules on restrictive business practices".
Officials did not name the specific airlines involved, but BA, Air France-KLM and SAS confirmed they had each received the European Commission letter.
It follows a lengthy investigation on both sides of the Atlantic dating back to early 2006 to discover whether airlines broke competition law by operating a cartel in the air cargo sector.
But EU officials stressed that the statement of objection did not reflect the final outcome of the investigation.
The airlines have all committed to co-operate fully with the authorities.