Published: Oct 11, 2012 2:54 PM EDT
Updated: Oct 12, 2012 6:31 AM EDT

NEW YORK (AP) - Executives at some of the country's largest private equity firms told each other they wouldn't drive up prices for companies they were looking to buy, according to newly released court documents.

A complaint released Wednesday by a federal district court in Boston details exchanges between executives at Blackstone Group LP, Carlyle Group LP and other private equity giants. It's part of a long-running lawsuit charging the firms with rigging bids for 19 buyouts, including deals for Neiman Marcus, Toys "R'' Us and the hospital chain HCA.

The plaintiffs in the class-action case are former shareholders in the companies bought by the private equity firms. Their lawsuit names nine of the largest private equity firms along with Goldman Sachs Group Inc. and JPMorgan Chase & Co. as defendants.