(Adds Caixas comments)
SAO PAULO, Dec 14 (Reuters) - The pension fund for oil company Petroleo Brasileiro SA's employees on Wednesday called for securities industry watchdog CVM to investigate some of Brazil's largest asset managers over allegations of irregularities, a statement said.
Walter Mendes, president of Fundação Petrobras de Seguridade Social, commonly known as Petros, asked CVM to look into the reasons for losses in investments managed by asset management units of Banco Bradesco SA and Caixa Economica Federal.
Petros also asked the regulator to investigate Mantiq Investimentos Ltda, previously owned by Banco Santander Brasil SA, and Mare Investimentos.
Petros alleged that the banks' asset management units either had conflicts of interest or violated the guidelines agreed to manage the investments, which resulted in losses for Petros.
Bradesco declined to comment. Caixa said it has not been notified about the issue and that another asset manager was responsible for the investment cited by Petros as having resulted in losses.
Mantiq and Mare did not respond immediately to requests for comment. (Reporting by Tatiana Bautzer; Editing by Bernard Orr and Jonathan Oatis)