Connecticut Retirement Plans and Trust Funds, Hartford, reached a $457 million settlement in a securities fraud case against Waste Management Inc. The settlement, announced by state Treasurer Denise L. Nappier, is the third-largest class-action settlement in U.S. history. The $20 billion system, which was lead plaintiff in the suit, claimed Waste Management failed to properly disclose to investors serious problems related to the merger between U.S.A. Waste Services and the former Waste Management Inc. in 1998, and that certain company officials allegedly engaged in insider trading during 1999. The settlement also included a series of reforms in the companys corporate governance policies advocated by Ms. Nappier. As of Oct. 12, the Connecticut system owned 455,862 shares of the stock with a value of $12.4 million.