* Biggest houses need only cover failure by largest member * CFTC had previously proposed coverage of top two members Oct 18 (Reuters) - The U.S. Commodity Futures Trading Commission backed away, at least for now, from a plan that imposed heightened financial resource requirements on systemically important clearinghouses whose failure could imperil the market. As part of its Dodd-Frank financial oversight law rulemaking, the CFTC had initially proposed requiring systemically important clearinghouses to maintain enough funds to cover the default of their two largest members. Any other clearinghouse, by contrast, would need only enough money to cover the default of its largest member. But in the final rules on Tuesday, the CFTC will require clearinghouses only to have enough funds to cover a default by their largest member, regardless of whether they are dubbed systemically important. The CFTC's announcement on Tuesday was part of a broader rule the agency passed in a 3-2 vote that outlined guidelines for clearinghouses -- the middle man between buyers and sellers of exchange-traded derivatives. Commissioners Jill Sommers and Scott O'Malia, both Republicans, cast the dissenting votes. The regulator's rule outlined requirements for clearinghouses including financial resources, default rules, settlement procedures, treatment of funds and reporting and record keeping. "I think this is one of the most important regulations to lower risk in financial markets," Gary Gensler, the CFTC's chairman, said at a rulemaking meeting. The CFTC rule included a requirement of $50 million minimum net capital for firms to become clearinghouse members. For now, the CFTC said it would not move forward on a measure to heighten financial resource requirements on systemically important clearinghouses. The capital requirement comes in below ICE Clear Credit, the world's top clearer of credit default swaps (CDS), which requires $100 million of adjusted net capital from members. In July, parent IntercontinentalExchange Inc lowered the requirement from $5 billion. "In the absence of a rulemaking from CFTC at the time that Dodd-Frank deemed ICE Clear Credit a derivatives clearing organization, ICE put in place membership requirements for CDS that are more open than those of any other clearinghouse," ICE said in an email, adding it would work with the CFTC to protect the clearinghouse from the risks of participants. Rival CME Group Inc requires $500 million in capital from CDS clearing members. Under Dodd-Frank, any clearinghouse dubbed "systemically important" by the Financial Stability Oversight Council (FSOC) could gain access to some of the Federal Reserve's loan programs, including the discount window. A CFTC staffer who spoke with reporters late on Monday said the CFTC backed off its original plan pending negotiations with the FSOC and international regulations. "It was just premature at this time to do it," he said.