(Corrects next to last paragraph of April 8 story to show U.S.dollar is only ISDAfix rate collected by ICAP)
By Douwe Miedema
WASHINGTON, April 8 (Reuters) - The top U.S. derivativesregulator is probing a widely used benchmark for swaps, thetrade body overseeing the rate said, dealing a further blow tothe opaque market after the sprawling Libor probe.
The Commodity Futures Trading Commission (CFTC) hassubpoenaed the International Swaps and Derivatives Association(ISDA) over its ISDAfix benchmark, widely used toanchor market rates, a spokeswoman for ISDA said.
Bloomberg reported on Monday that the CFTC was investigatingderivatives broker ICAP Plc and as many as 15 banks in a probe into the possible manipulation of the benchmark.
The CFTC, which oversees the $640 trillion derivativesmarket, wants to know if ICAP's staff were colluding with thebanks, who stand to profit from inaccurate quotes, Bloombergsaid, quoting people familiar with the matter.
The CFTC did not immediately return a request for comment. Aspokesman for ICAP declined to comment.
The CFTC's probe came about as it was working with Europeanregulators in the scandal surrounding the Libor interbank ratebenchmark, which has lead to have fines for UBS AG,Royal Bank of Scotland Group Plc and Barclays Plc, Bloomberg said.
The fixings are based on a survey of panel banks for thedifferent currencies, according to the ISDA website. ICAPcollects the contributions for the U.S. dollar rate and sendsthem on to Thomson Reuters Corp, which calculates thefixing.
A spokeswoman for Thomson Reuters had no immediate comment. (Reporting by Douwe Miedema; Editing by Andre Grenon)