The Interfaith Center on Corporate Responsibility is asking 21 U.S. companies about differences between how they pay their top executives and how they pay their lowest-paid U.S. workers.

The ICCR, New York, represents about 300 church organizations, pension funds for religious workers, and other organizations that consider religious concerns when making investments.

ICCR member organizations have filed shareholder resolutions asking the target companies to describe the total compensation packages of the company’s top U.S. executives and the lowest-paid U.S. employees (including health care benefits and costs), for July 2000, July 2004 and July 2009.

The ICCR also is asking for an analysis of any changes in the relative size of the gap between the two groups.

The target companies include CIGNA Corp., Philadelphia (NYSE:CI); Coventry Health Care Inc., Bethesda, Md. (NYSE:CVH); Humana Inc., Louisville, Ky. (NYSE:HUM); Lincoln National Corp., Radnor, Pa. (NYSE:LNC); UnitedHealth Group Inc., Minnetonka, Minn. (NYSE:UNH); Unum Group Corp., Chattanooga, Tenn. (NYSE:UNM); and WellPoint Inc., Indianapolis (NYSE:WLP).