CME Group and IntercontinentalExchange Inc moved over the weekend to limit the fallout from the MF Global bankruptcy on futures markets by lowering margin requirements on some accounts.

The CME also said Monday that it has asked brokers who have taken over customer accounts from MF Global , which filed for bankruptcy Oct. 31, to not disburse any of the money until the close of business on Tuesday as it looks to verify the amounts involved.

The margin reduction for MF Global clients is aimed at providing "market relief to customers whose accounts have been disrupted by this event," the Chicago-based CME said in a statement Saturday.

Traders had worried that a rush to cover margin requirements on frozen MF Global accounts transferred to other brokers could lead to heightened market volatility.

The initial margin ratio has been cut to 1, allowing customers to meet the so-called maintenance margin levels, CME said. Initial margins are in place to provide an additional buffer against future losses.

Initial margins are the amount required as collateral when starting a trading position.

"The margins differed according to products," Jeremy Hughes, a Singapore-based spokesman at CME, said in an e-mail response to queries.

IntercontinentalExchange Inc , which operates the London-based ICE Futures Europe, said in a statement that ICE Futures U.S. is temporarily lowering the initial margin rate for all speculative accounts to a level equal to the maintenance margin rate for all contracts.

"This action is being taken to mute the impact of the transfer of accounts from MF Global Inc. to other clearing members," the exchange said.

ACOUNTS ON HOLD

The collapse of MF Global comes at a time when the Commodity Futures Trading Commission, Securities and Exchange Commission and bank regulators are writing some 400 new rules required by last year's Dodd-Frank financial reform law.

There have been conflicting reports about the whereabouts of $633 million of missing customer money, whose disappearance derailed MF Global's effort this week to quickly sell a variety of assets.

The changes heightened futures firms' concern of an increase in operational costs and limits on how they invest customer funds for their own benefit.

CME Group, the biggest operator of U.S. futures exchanges, has directed members to delay the distribution of transferred funds and proceeds of the liquidation of any transferred positions until the calculation is over.

The calculation is expected to be completed by the close of business on Nov 8.

"'New' funds deposited by customers may be freely withdrawn," the CME said in its notice.

"We will notify firms promptly as customers' accounts are verified and the hold is lifted."

(Additional reporting by Antonita Devotta in BANGALORE; Editing by Michael Urquhart)