IntercontinentalExchange Inc. (ICE) this week began clearing live credit default swap transactions, a key step toward mitigating systemic risk in the $28 trillion market.

The move comes as ICE Trust, the credit derivatives clearinghouse launched by the Atlanta-based exchange in early March, crossed the $100 billion threshold in notional value of trades cleared.

ICE Trust remains the only clearinghouse for credit derivatives in the U.S. and the only such platform to do any business on either side of the Atlantic.

Chicago-based CME Group Inc. (CME) is readying its own CDS clearing and trading solution, a joint venture with the hedge-fund firm Citadel Investment Group, though no launch date has been set.

NYSE Euronext (NYX) rolled out its own clearing platform for credit derivatives in London last December, but, as of this month, that service had yet to handle any trades.

Up until this week, ICE Trust had been clearing pre-existing trades, as dealer banks backloaded positions into the clearinghouse.

Credit default swap indexes remain the only sort of credit derivatives clearable through ICE Trust, though ICE plans to eventually expand clearing capabilities to single-name instruments.

Authorities in the United States and Europe have pushed CDS dealers to clear credit derivatives trades, in a bid to improve efficiency and reduce the systemic risks exposed by the near-collapse of American International Group Inc. (AIG) last fall.

-By Jacob Bunge, Dow Jones Newswires; 312-750-4117; jacob.bunge@dowjones.com