S.Korea says to probe local impact of global forex scandal

* Antitrust body says investigating impact on S.Korea firms

* 6 global banks recently fined after U.S., Europe forex probe

* Unclear whether S.Korea probe will result in any sanctions (Adds details, comment, background)

By Lee Chang-ho and Joyce Lee

SEOUL, June 17 (Reuters) - South Korea's antitrust regulator said on Wednesday it is investigating whether the actions of six global banks recently fined nearly $6 billion in a U.S. and European forex probe had any impact on local firms.

Fair Trade Commission Chairman Jeong Jae-chan told a parliamentary hearing the regulator is examining whether there are grounds for sanctions against the six banks, without giving specific details.

Yim Jong-yong, head of the financial industry regulator, also told lawmakers his agency would assist in the probe.

It was not immediately clear whether the investigation will result in formal sanctions.

The six banks involved in the global foreign exchange rates scandal were Citigroup Inc (NYSE: C - news) , JPMorgan Chase & Co (Xetra: 850628 - news) , Barclays Plc (LSE: BARC.L - news) , Royal Bank of Scotland Plc, UBS AG and Bank of America Corp.

Four of them - Citigroup, JPMorgan (LSE: JPIU.L - news) , Barclays and Royal Bank of Scotland - pleaded guilty in May of trying to manipulate foreign exchange rates, and along with UBS (NYSEArca: FBGX - news) and Bank of America, were fined nearly $6 billion in another settlement in the global probe.

A case against any of those banks in South Korea could be difficult to prove, as the FTC would need to determine whether their actions affected local market rates such as won-dollar, an antitrust lawyer at a large domestic firm said, declining to be named as he was not authorised to speak to the media.

"It's a complicated case. Depending on how well the connections can be made, the FTC could drop it early or it could take a while," the lawyer said.

In the U.S. and European probes, investigators focused on activity in the euro-dollar exchange rate, but those benchmarks have little bearing on the South Korean market, as the rates are typically set when the onshore spot market is closed, a local bank executive said, declining to be identified because he is not authorised to speak with the media.

Barclays, Citigroup, Bank of America, JPMorgan and UBS declined to comment on Wednesday on the South Korea probe. RBS (LSE: RBS.L - news) could not immediately be reached for comment.

So far, the forex scandal has had a limited impact in Asia. Last December, the Hong Kong Monetary Authority said it found no evidence of rigging in its foreign exchange benchmarks, but identified "inappropriate" behaviour by individual traders.

In Singapore, the region's largest forex trading centre, the central bank has not launched a standalone probe, but has said it is willing to assist foreign regulators.

In 2012, the South Korean antitrust body said it began an investigation into banks and brokerages on suspicion of collusion in setting three-month certificate of deposit rates.

The agency has said it will announce its findings as quickly as possible but has yet to do so. (Additional reporting by Se Young Lee, Yena Park and Joshua Franklin; Editing by Tony Munroe and Miral Fahmy)