(Reuters) - CME Group Inc (>> CME Group Inc), the world's largest futures exchange operator, said it would temporarily raise the margins on some products traded on its platform on Wednesday, citing likely market volatility as a result of the U.S. debt ceiling debate.

Derivative exchange and clearing house operator IntercontinentalExchange Inc (>> IntercontinentalExchange Inc) (ICE) said it was monitoring the situation, as did clearing and settlement services provider Depository Trust & Clearing Corp (DTCC).

The move by CME was yet another instance of global trading houses taking steps to shield themselves from a spike in volatility, even as trading volumes have fallen across financial markets in the first two weeks of October.

"Anticipating possible market moves specific to this event, CME will increase margin for all OTC IRS portfolios by applying the Event Risk margin add-on of 12 percent to the base margins," CME said in a statement, referring to over-the-counter interest rate swaps.

The additional margin will be implemented across four days, with the first 3 percent increment beginning at the end of Wednesday, CME said.

Some market participants using Nasdaq OMX Group Inc's (>> NASDAQ OMX Group, Inc.) U.S. Treasuries platform, eSpeed, have also had their margins raised, a person familiar with the matter said. Nasdaq uses the Fixed Income Clearing Corp, a subsidiary of DTCC, for clearing Treasuries, sending it though a clearing member of FICC.

Nasdaq declined to comment.

The DTCC said it has not yet made any changes to its approach to discounts on collateral.

"DTCC continues to monitor overall market activity, with a particular focus on the Treasury market and are assessing if we will need to make any types of adjustments in our valuations of securities required for collateral in our clearing fund," the clearing house operator said in a statement.

Similarly, ICE said it was communicating with regulators and working with its clearing members while monitoring the risks in the market. It said it would take steps to mitigate those risks as appropriate.

There has been less volatility in the equity markets than the derivative markets during the debt debate.

A spokesman for BATS Global Markets said it was "business as usual" for the U.S. equity market operator. No. 1 U.S. stock exchange operator NYSE Euronext (>> NYSE Euronext) declined to comment.

The U.S. House of Representatives was set to vote on a deal over the fiscal impasse on Wednesday after the Senate struck a last minute deal to avoid a historic lapse in the government's borrowing authority. President Barack Obama has said such a breach could lead to default and deliver a damaging blow to the global economy.

Last week, Hong Kong Exchanges & Clearing (HKEx) said it would apply a deeper discount on U.S. Treasuries used as margin collateral, according to a circular from the clearing house.

HKEx, the holding company for The Stock Exchange of Hong Kong Ltd, Hong Kong Futures Exchange Ltd and Hong Kong Securities Clearing Company Ltd, will now apply a haircut of 3 percent versus the current 1 percent for bills with a maturity of less than a year. The haircuts applied to longer-dated bills remain unchanged.

(Reporting by Saikat Chatterjee in Hong Kong, Claire Milhench in London, and John McCrank in New York; Editing by Kim Coghill and Andre Grenon)