Nov 5 (Reuters) - Derivatives market participants are creating repositories to provide regulators with information necessary to spot system-threatening risk exposures in the $600 trillion market. [ID:nL5525440]

Below are descriptions of the companies forming those repositories. These firms already collect much of the information on trades from major dealers as part of their normal businesses, giving them an advantage in moving quickly.

* Interest-rate derivatives:

TriOptima already helps derivatives dealers and investors identify and reconcile any differences in their mark-to-market valuations of swap contracts on a regular basis so they are in a position to analyse counterparty risks and avoid disputes about collateral.

The technology firm is best known so far as a leader in portfolio compression in credit default swaps, the business of cutting the number of contracts without changing the underlying risk exposure.

* Equity derivatives and credit derivatives

The Depository Trust & Clearing Corp (DTCC) provides clearing, settlement and information services for a number of markets. In the credit derivatives market, it operates the Trade Information Warehouse and global repository among other services.