The Daily News reports that the announcement comes nine days before the premiere of Anna Nicole, the company's co-production with the Brooklyn Academy of Music.
City Opera Artistic Director George Steel says the company needs the money both for the rest of this season and for it "to continue forward on solid financial footing".
The company has embarked on a $20m fundraising effort.
The City Opera left its permanent home at Lincoln Center in 2011. That helped balance its budget. Now, Steel says what the company needs "is the stable funding that will make our work possible".
Unlike the Metropolitan Opera, the City Opera is devoted to bringing opera to the masses. Last year, City Opera made more from its thrift shop on East 23rd Street in Manhattan than from its endowment.