A federal judge in Chicago granted preliminary approval of a proposed class action settlement Friday to provide $10 million in increased pension benefits to more than 1,700 participants and beneficiaries in two of Citgo Petroleum Corp.'s pension plans.

U.S. District Judge Matthew Kennelly of the Northern District of Illinois granted preliminary approval Friday after counsel with Cohen Milstein filed the class action settlement agreement Wednesday on behalf of the three former Citgo employees, Leslie Urlaub, Mark Pellegrini and Mark Ferry. The lawsuit, Urlaub v. Citgo Petroleum, alleged that the Houston-based gas and energy company failed to properly calculate joint and survivor annuity benefits for married retirees and imposed a "marriage penalty" that reduced the joint pensions below the value of pensions paid to single retirees, in violation of the federal Employee Retirement Income Security Act (ERISA).