Mimi Eng, a v.p. in the structured product group at J.P. Morgan Securities, was recently laid off, says a collateralized debt obligation official at the firm. She was a CDO structurer, reporting to Romita Shetty, managing director and head of the global CDO business for the firm. Eng could not be reached for comment. Shetty did not return calls seeking comment on whether Eng's spot will be filled.