Seeking to resolve confusion and conflicting reports in the media and the blogosphere, the Credit Suisse Index Co. said that the collapse of two Bear Stearns hedge funds would have a minimal impact on its main index, but that its fixed-income arbitrage subindex was not so lucky.

The Bear Stearns High Grade Structured Credit Fund—the one deemed not quite a total loss by the New York investment bank last week—is one of 437 funds making up the Credit Suisse/Tremont Index, with a weight of less than 0.2%, Credit Suisse said today. As its collapse will “have limited impact on the overall performance” of the index, the June performance numbers released on July 16 will not be revised.

The Credit Suisse/Tremont Fixed Income Arbitrage Sector Invest Index was not so lucky: the Bear fund was one of just 10 components, with a weight of 9.86%. But CS notes that “on Monday morning, July 16, a value of ‘NA’ was reported for SECT FIARB as the performance of the Bear Stearns HGSC Fund was deemed to be of material importance to the calculation of the overall index and reported to be announced later that day by Bear Stearns.” When Bear did report, on July 17, it sent the fixed-income arb subindex down 5.98% for June. It is down 7.47% year-to-date.

CS said the Bear funds would not affect any of its other strategy subindices, nor its investable indices.