[Update 1: Corrects date and provides clarification of second paragraph.] Mortgage bond investors are more aggressively launching legal actions to preserve the integrity of the contracts they signed on residential mortgage-backed securities. However, it is unclear if the jump is due to upcoming statutes of limitations, pressures from attorneys to file, or the simpler pursuit of justice. The Patton Boggs Mortgage Litigation Index, which measures mortgage lawsuits, rose to its highest level in four years, based on a surge in MBS and investor litigation. In the third quarter of 2010, there were only 23 investor cases. That number rose to 50 in the second quarter of 2011 and 82 in 3Q2011. MBS litigation, a separate category, grew from 12 cases in the third quarter of 2010 to 62 cases in the third quarter of 2011. The Patton Boggs law firm said MBS-related activity was the greatest contributor to growth in the mortgage space. Other areas, such as foreclosure case, also saw increases but to a lesser degree. Mortgage servicing cases, by way comparison, declined quarterly. "The increase in MBS litigation is partly driven by statutes of limitations on investors’ claims. State claims against originators for alleged mishandling of portfolios, inadequate underwriting practices and misrepresentations regarding loan quality on the part of private and GSE litigants can only be preserved by filing lawsuits before claims expire," said Patton Boggs partner Patrick McManemin. MortgageDaily reports the index is at its highest level since publication began in 2007. Chris Katopis with The Association of Mortgage Investors says members are watching closely as attorneys compel RMBS Trustees to dig through pools of mortgages to detect instances where investors did not receive transparent information on poorly underwritten mortgages. Katopis said the association watched in great interest when a Trustee filed a $95 million representation and warranties case against JPMorgan Chase, claiming the defendant provided inaccurate statements about the quality of mortgages placed in trust and sold off to RMBS investors. In a letter to a trust administrator for JPMorgan Chase (JPM) last summer, AMI members said investors were having trouble gaining information on the underlying contracts to enforce claims, putting them in a situation where they could not mitigate future losses. The association wrote, "Given the overwhelming evidence presented… you can no longer ? look the other way and remain uninvolved. Instead, as trustee, you have certain obligations under the pooling and servicing agreements governing RMBS trusts. You hold the collateral (e.g., mortgage loans and documents) for the benefit of the Trust and its beneficiaries – the certificateholders." Reps and warranties issues are specifically troubling to RMBS investors. The reps and warranties clause is a type of assurance, guaranteeing parties to a transaction that the mortgage quality reaches a certain level. This information can play a vital role in an investor's decision to buy or forego a deal.  For investors, a breach of this clause can lead to far-reaching losses on their investments or suggest they were not provided the correct information when signing the original deal. AMI currently has $300 billion of MBS assets under trustee management and a large part of those assets are first-lien mortgages residing in private label RMBS. With policy makers and the mortgage finance industry trying to turn the RMBS market back towards an aggressive private-label model, Katopis and the association are advising players in the industry to remember that investor confidence must be preserved. In the same letter, AMI told the JPMorgan trust administrator that "to revive the U.S. housing market and restore the securitization market to working order, it is imperative that outstanding issues relating to 2005- to 2008-vintage mortgage securities be resolved in a manner that does not alienate private investors by disregarding their contractual rights or encouraging opacity." Write to Kerri Panchuk.