According to a complaint filed Tuesday night in a New York state court in Manhattan, Citigroup breached its duties as trustee for the 25 private-label trusts dating from 2004 to 2007 by ignoring “pervasive and systemic deficiencies” in how the underlying loans were underwritten or being serviced. The investors said Citigroup looked askance at the loans’ “abysmal performance” out of fear it might “jeopardize its close business relationships” with loan servicers including Wells Fargo & Co and JPMorgan Chase & Co, or prompt them to retaliate over its own problem loans.