BRUSSELS, April 28 (Reuters) - EU antitrust regulators on Wednesday fined Bank of America Merrill Lynch, Credit Agricole and Credit Suisse a total of 28.5 million euros ($34.4 million) for taking part in a bond cartel. Deutsche Bank was not penalised because it alerted the cartel to the European Commission. The EU competition watchdog said the cartel was operated in the European secondary trading market related to supra-sovereign, sovereign and agency (SSA) bonds denominated in U.S. dollars.