Politics weigh as Korea's KEPCO eyes the Toshiba nuclear option

* KEPCO one of few firms with global nuclear ambitions

* But won't rush to bid for Toshiba business - sources

* Would want clarity on Westinghouse liabilities

* U.S., Korean political uncertainty not helping (Adds KEPCO comment, debt)

By Jane Chung and Geert De Clercq

SEOUL/PARIS, March 24 (Reuters) - South Korea's KEPCO , the likeliest suitor for Toshiba Corp's troubled nuclear business, is holding off from making an approach because of question marks over the scale of damage at the unit and political uncertainty in both South Korea and the United States, people with direct knowledge of the matter say.

Japanese TV-to-rail conglomerate Toshiba has been battered by a $6.3 billion hit from overruns in the nuclear business and has widened a probe into governance failures at its U.S.-based unit, Westinghouse. It is now considering a sale.

State-controlled Korea Electric Power Corp (KEPCO), one of few utilities with global nuclear ambitions, has developed its own technology and led a consortium in 2009 that won a contract to build four reactors in the United Arab Emirates.

Unlike Westinghouse and France's Areva, whose new third-generation reactor models have faced years of delays and big cost overruns, KEPCO has managed to build its reactors abroad on time and to budget.

This positions the Korean firm as a major new player in nuclear reactor manufacturing at a time when Westinghouse and Areva, the two leading OECD nuclear firms, are struggling.

KEPCO aims to build six more reactors abroad by 2025, targeting markets like Britain and South Africa.

But the utility, with $44.6 billion of debt as of December 2016, is in no rush to acquire Toshiba's business, the people said, as it needs clarity on the potential Westinghouse baggage - in terms of liabilities, but also intellectual property.

That could mean months, or even years, of waiting, one said.

"We are monitoring the situation and nothing has been made official," a KEPCO spokesman said.

POLITICAL VACUUM

More pressingly, domestic uncertainty after the impeachment of South Korea's president has made it tougher to secure political backing for a risky nuclear deal.

One official involved in the matter said KEPCO and Korea Hydro & Nuclear Power Corp (KHNP) could not move without state support: "The project has a chance of backfiring on us as everything is unpredictable, so it's a hot potato."

And in the United States, there is little clarity over nuclear policy under President Donald Trump, and several key positions are vacant.

One senior industry source said any move by KEPCO could require pre-approval by the U.S. government - complex even if South Korea is likely one of few palatable options.