Assured Guaranty (AGO) claims more than 7,300 mortgage bonds sold by Credit Suisse (CS) subsidiary DLJ Mortgage Capital contained undisclosed underwriting issues.

The bond insurer alleges it guaranteed the six related residential mortgage-backed securities deals, only because it did not know the product lacked appropriate due diligence.

Assured Guaranty made those claims in New York county court records as the company battles the defendants for compensation on insurance payments covering claims tied to bad mortgages.

In response to the defendants’ motion to dismiss the case, Assured filed the brief highlighting what it considers to be defects in the deals.

Assured said, “the extent of DLJ’s breaches is astonishing — approximately 93% of the 7,918 mortgage loans that Assured has reviewed breached one or more of the representations.”

The insurer also noted it found 7,336 defective mortgages with an original principal balance of $1.8 billion. Those mortgages are part of six securitized transactions the bond insurer guaranteed for Credit Suisse and DLJ Mortgage.

The defendants are trying to get the case dismissed on several grounds, including a claim that Assured waived its right to certain damages since it accepted insurance premiums under the policies.

Assured claims acceptance of premiums is not a bar to rescissory damages.

Write to Kerri Panchuk.