GRAPHIC-Brexit tremors spread to UK-exposed London stocks

* Financials, retail and travel seen as most affected

* Miners and oil shares outperform after rough start to year

* Graphic: http://reut.rs/1n1c0Ar

By Alistair Smout

LONDON, Feb 26 (Reuters) - Brexit fears appear to be affecting the UK stock market for the first time this week, as Britain's more globally exposed shares outpace those that could be hit harder should the country vote to leave the European Union.

Some of Britain's biggest banks are seen as most at risk from a possible Brexit in the June 23 vote, and along with retailers, construction and travel firms, they have begun to underperform the market.

As the following graphic shows - http://reut.rs/1n1c0Ar - the globally exposed FTSE 100 is now outperforming the more domestically focused mid-cap FTSE 250.

Earlier this year, it was the FTSE 100's international exposure that hindered its performance. However, now that a date has been set for the referendum on Britain's EU membership, more domestically exposed sectors have moved into focus.

Stocks most exposed to Brexit are the underperformers among the biggest 350 London-listed companies, as commodity stocks with exposure to the global economy, such as miners and oil, have more than recovered ground lost earlier this year.

HSBC has said labour-intensive services and retail sectors would suffer if Britain quit the EU, as labour costs would likely rise, with the construction industry also affected.

Property could be doubly hit if the real estate market, which in parts of Britain is highly dependent on foreign buyers, falters.

Travel and leisure is seen as vulnerable both to reduced demand for holidays abroad due to a weaker pound and possible border issues, as well as a tightening labour market.

"Many of the low-wage sectors would be hit... and if there is a nasty fall-out, we could see fewer visitors going to the continent," Chris Beauchamp, market analyst at IG (LSE: IGG.L - news) , said.

"Everyone has June pencilled in as the end date for that uncertainty, but there could be a lot more to come after the vote itself."

Banks could see funding costs rise in the event of Brexit, according to analysts at Societe Generale (Swiss: 519928.SW - news) , and could see consumer confidence hit and business shift to places that were still in the EU to gain access to the single market.

As such, the sector is among the FTSE 350's biggest fallers this year, along with insurers, many of whom also have substantial European operations.

Societe Generale analysts share the view of many other investment banks and fund managers, who think Britain will vote in June to stay in the EU.

Nevertheless, SocGen (Paris: FR0000130809 - news) analysts still saw Brexit as the main risk for UK banks, and singled out Barclays (LSE: BARC.L - news) and Royal Bank of Scotland.

"On a tough view of the Brexit consequences, we estimate a 10-12 percent EPS cut for Barclays/RBS (LSE: RBS.L - news) , but we think that this likely overstates the case," they said in a note. "However, sentiment could swing around if polls remain close."

(Additional reporting by Kit Rees; Editing by Hugh Lawson)