In a big win for business, the Treasury proposed on Friday to exempt commonly used foreign exchange swaps and forwards from new rules that have tightened oversight of other derivatives.

The Treasury Department said that forcing these derivatives through clearinghouses and onto exchanges was not necessary because existing procedures in the foreign exchange market mitigate risk and ensure stability.

Any disruptions to this market could have serious negative economic consequences, the department said.

Foreign exchange swaps and forwards, which represent about 5 percent of the $600 trillion over-the-counter derivatives market, are used by a wide range of companies to lock in prices as protection against exchange rate fluctuations.

Businesses, big banks and the securities industry had furiously lobbied the Obama administration to exempt the financial instruments from the new rules. They argued, among other things, that clearing requirements were unnecessary given that most contracts expired after one week.

The Treasury agreed.

You would be putting more steps into the settlement process for trades that are largely short-term in nature, Mary Miller, the Treasury's assistant secretary for financial markets, told reporters.

FINAL DECISION MAY CHANGE

Under the Dodd-Frank financial reform legislation enacted last year, the Treasury secretary was given the power to determine whether the narrow subset of foreign exchange derivatives should be tightly regulated.

The rest of the over-the-counter derivatives market will be forced through clearinghouses, which will stand between two parties and assume the risk if one party defaults.

The country's biggest labor federation, the AFL-CIO, criticized the Treasury's plan and said it would create a loophole that could be exploited.

We're afraid it is going to open up an opportunity for arbitrage in which derivatives users look to employ the least-regulated products, said Heather Slavkin, the AFL-CIO's senior legal and policy adviser.

The legislation was aimed, in part, at trying to ensure derivatives no longer pose the type of threat they did during the 2007-2009 credit crisis. Credit derivatives were implicated in the downfall of troubled financial giants Lehman Brothers and AIG.

The Treasury's Miller said the foreign exchange swaps market was different from other derivatives markets and that under Dodd-Frank it would be illegal to use the instruments to evade tougher scrutiny that applies to other derivatives.

The proposal is open for comment for 30 days. The Treasury's final decision will be issued after that period. Officials said they would not speculate on whether the proposal would change.

The swaps and forwards would also be subject to trade reporting requirements and business conduct standards.

James Kemp, managing director of Global FX Division, who lobbied for an exemption, said he hoped European regulators would follow the Treasury's lead.

(Additional Gertrude Chavez-Dreyfuss and Wanfeng Zhou in New York, and Dave Clarke and Glenn Somerville in Washington; Editing by Andrew Hay and Dan Grebler)