Everyone knows that when Bank of America acquired Countrywide, it inadvertently picked up a time bomb of mortgage-backed securities liability. Last summer you could hardly turn on the computer without hearing about another MBS investor suit claiming Countrywide (and its purported successor, BofA) committed securities fraud when it offered MBS notes. And that was on top of bond insurer suits and investors' breach of representations and warranties claims.

Now, suddenly, there's a boomlet in MBS claims against JPMorgan Chase, stemming in large part from its acquisitions of Bear Stearns and Washington Mutual Bank. On Friday, the troubled Belgian bank Dexia sued all three in Manhattan State Supreme Court over losses it sustained in its $1.7 billion investment in Bear and WaMu MBS. The new complaint, filed by Dexia's counsel at Bernstein Litowitz Berger & Grossmann, follows four suits Bernstein Litowitz filed this fall against Bear and JPMorgan on behalf of German financial institutions. And as I wrote at the time, I'm expecting more where those came from.

Moreover, the Gibbs & Bruns investor group that negotiated the proposed $8.5 billion put-back settlement with BofA is also targeting JPMorgan. In December, the Gibbs group (which notably includes PIMCO and Black Rock), directed five MBS trustees overseeing Bear, WaMu, and JPMC trusts to open investigations of the underlying mortgages, searching for breaches of the reps and warranties the MBS sponsors offered on the loans.

The Bernstein Litowitz suits for Dexia and the German institutions assert that JPMorgan is the successor-in-liability to Bear Stearns and WaMu. That's hardly an established fact, however. (Remember, successor liability remains an issue in BofA MBS litigation as well, which is one of the reasons the Gibbs group settled put-back claims for $8.5 billion.) Bond insurers have been out front in litigation against JPMorgan Chase, just as they have in every phase of MBS litigation. Ambac, for one, has been permitted to pursue claims against the bank that stem from Bear's mortgage-origination unit. But JPMorgan's ultimate responsibility for Bear and WaMu mortgage-backed notes is a long way from being settled; Syncora's case against the Bear unit, for instance, doesn't name JPMorgan.

A JPMorgan spokesman declined comment.

(Reporting by Alison Frankel)