S&P Dow Jones Indices is working with startup exchange trueEX to offer futures contracts tied to credit-default swaps, the latest volley from firms vying for a piece of the rapidly evolving CDS market.

The index unit of McGraw-Hill has agreed to let trueEX base the CDS futures on three newly created CDS indexes. The resulting futures will track the top 150 largest debt-issuing companies within the S&P 500 equity index, becoming the first credit-derivatives indexes to focus on that widely watched benchmark.