A federal judge eased the burden of evidence Syncora Guarantee (SCA) must meet as it attempts to compel EMC Mortgage Corp. to re-acquire toxic home equity lines of credit that Syncora is insuring under an agreement. The defendant, EMC Mortgage Corp., is now part of JPMorgan Chase (JPM) after being acquired by the bank three years ago. Syncora filed the original suit against EMC Mortgage Corp. in 2009, alleging the mortgage servicer breached representations and warranties made to the insurer on 9,871 HELOCs residential mortgage loans. The HELOCs were used as collateral on a transaction that involved the issuance of $666 million in securities offered to the public, court records say. EMC Mortgage is accused in the original complaint of aggregating the HELOCs and selling the pool, with Syncora providing the insurance to protect investors. Syncora claimed in its original complaint that EMC breached representations made to the insurance firm on 85% of the loan pool insured under the agreement. The legal issue decided by the court on March 25 involved Syncora's motion for summary judgment on the grounds that the insurer could base its claim against EMC using data extrapolated from "a random sampling of 400 loans out of 9,871." EMC countered that claim, saying Syncora would have to seek relief by arguing the merits of its case on a loan-by-loan basis. The court disagreed with EMC, granting Syncora's motion for partial summary judgment on that issue and allowing it to push forward with its claim using a sample from the entire loan pool. On the same day, Syncora lost its bid to amend its complaint against EMC by adding Bear Stearns & Co. -- now known as J.P. Morgan Securities -- as an additional defendant in the case. The judge rejected this motion, saying Syncora's motion to add Bear Stearns is void because of its "untimeliness." Write to Kerri Panchuk.