As JPMorgan & Chase Co. (JPM) looks to digest its bail-out of Bear Stearns, once the biggest player in the private-party mortgage-backed securities space, questions appear to be bubbling to the surface regarding the value of Bear’s own mortgage book. Let’s just say that the questions aren’t around a possible undervaluation of mortgage- related assets. HW’s sources have suggested for at least a month that JPMorgan executives would need to reconcile the values assigned in Bear Stearns’ mortgage book with valuation methods already in place at JPMorgan. While none of our sources have explicitly said that Bear’s mortgage book is misvalued, news from the Financial Times over the weekend suggests that some problems may yet be in the offing:

Two senior Bear Stearns executives who moved to senior positions at JPMorgan Chase just weeks ago are leaving the bank. The departure of Jeff Mayer and Craig Overlander comes amid questions about the value of the Bear Stearns mortgage book … But they are leaving, partly because of problems with Bear’s mortgage portfolio. Their departure “is not exclusively because of marks on the mortgage book,” according to a person familiar with the matter, who added “there were plenty of other people involved with that”.

The FT report didn’t specify what “problems” were at issue, and JPMorgan press reps certainly haven’t commented on the issue publicly. Mayer and Overlander ran the fixed income department at Bear Stearns, but weren’t responsible for the original marks on Bear’s mortgage book. Disclosure: The author held no positions in JPM when this story was originally published. HW reporters and writers follow a strict disclosure policy, the first in the mortgage trade.