Standard & Poor's has added ACE Limited to its flagship S&P 500 Index as of the close of trading on July 14.

The addition was made possible by recent changes in eligibility criteria for inclusion in S&P's U.S. indices. Previously, companies were excluded from these indices if they were not incorporated in the U.S. or certain other “domiciles of convenience” such as Bermuda and the Cayman Islands. When ACE re-domesticated to Switzerland in 2008, it was removed from the S&P 500 and other U.S. S&P indices.

The new criteria place primary emphasis on the location of the stock exchange where the company’s shares are listed (e.g., NYSE) and the location of the majority of its assets, and no longer exclude companies solely on the basis of their place of incorporation.

As a result, S&P added ACE and several other eligible companies to the S&P Total Market Index on June 18, setting the stage for their potential inclusion in the S&P 500 and other S&P U.S. indices.  Russell Investments, which also maintains U.S. stock indices, added ACE to its Russell 1000 Index on June 25 based on similar inclusion criteria changes.