* U.S. regulator 'substantially' got it right -Greifeld
* Details of first few swaps rules proposed Oct. 1 (Adds quotes, background, byline)
By Jonathan Spicer
PARIS, Oct 11 (Reuters) - The head of Nasdaq OMX Group Inc, which controls a clearing house for interest rate swaps, on Monday endorsed the U.S. Commodity Futures Trading Commission's plan to limit the ownership of derivatives clearers.
The CFTC, which regulates U.S. futures, this month proposed to cap at 20 percent the voting stakes of each clearing house member -- its first steps in defining how the $615 trillion over-the-counter (OTC) derivatives market will operate in the wake of the 2007-2008 financial crisis.
"In the CFTC rules with respect to governance, I do believe they have substantially got the matter right," said Robert Greifeld, chief executive of the exchange operator that has a majority stake in the International Derivatives Clearing Group (IDCG).
"It's fundamentally important that the margin regime in the clearing house, and what is required to gain access to the clearing house, is a well thought out process," he added in an interview on the sidelines of the World Federation of Exchanges conference.
Excesses in the vast OTC market are blamed for exacerbating the crisis. The sweeping U.S. Wall Street reform law passed this year, known as the Dodd-Frank bill, will force much of that market into clearing houses and onto transparent trading platforms, seen as safer alternatives.
Clearing houses operate between buyers and sellers, reducing the risk a default by one firm will infect the broader market.
The CFTC also proposed collective ownership limits on Oct. 1. Banks, non-bank financial firms, swap dealers and major swap participants would not be allowed to collectively own more than 40 percent of a clearing house under the plan.
IDCG's clearing traffic has jumped in recent weeks, yet it is still a tiny fraction of the total interest rate swaps market, estimated at about $360 trillion.
"We clearly see great opportunity as over-the-counter derivatives come on to central clearing houses, and we've been focused on that for the last several years," Greifeld said. (Editing by Hans Peters and Michael Shields)