Citigroup Inc. (C) said it could lose overseas customers and Goldman Sachs Group Inc. (GS) may have to limit transfers of capital among its units because of new regulations designed to make the financial system safer.

New derivatives rules set by the Dodd-Frank Act may force foreign clients at overseas branches to comply with U.S. standards, a prospect some don’t find appealing, New York-based Citigroup said today in its annual securities filing.