Robert Hoffman has left Morgan Stanley where he was the firm's senior asset-backed securities banker specializing in rate reduction bond deals, according to an individual at the firm. Hoffman reported to Gail McDonnell, managing director and head of ABS finance. McDonnell did not return repeated calls seeking comment on the bank's plans to replace Hoffman or the reason for Hoffman's departure. Hoffman could not be reached for comment. A banker at Morgan Stanley says that Jack Kattan, v.p., also an ABS banker in McDonnell's group, would be filling in for Hoffman, but it remains unclear whether he would do so on a permanent or temporary basis. An ABS analyst outside the firm confirmed that Kattan is the de facto banker in charge of rate reduction transactions for the firm. Kattan declined to comment.