Microsoft Corp.’s efforts to prevent further investigation by the European Union into its Teams video-conferencing app were unsuccessful, as the bloc’s antitrust enforcers are preparing to file a formal complaint against the company’s behavior. Sources familiar with the situation, who requested anonymity, revealed that Microsoft’s recent suggestion to separate Teams from its comprehensive business software package and offer it to customers at a discounted annual rate did not address regulators’ worries. The European Commission is preparing a statement of objections to send to the company, which could come in the…