Excerpt: The International Brotherhood of Dupont Workers has sued the Wilmington-based chemical company and its pension fund, saying that company efforts to streamline its payroll system by hiring an outside contractor to manage it has led to workers' being shortchanged on their pension payments. The federal lawsuit, filed July 24 in the Eastern District of Virginia, involves four DuPont Co. facilities, including Philadelphia's. Affected are about 500 employees, including as many as 100 from Philadelphia, who retired after July or Aug. 2008, or will retire as Dupont seeks voluntary retirements to reduce layoffs.  MORE >>