US STOCKS-Wall St slips as countdown to Trump's swearing-in begins

* Trump to make inaugural speech on Friday

* Energy, financial, health sectors weigh on S&P

* Union Pacific up on profit beat

* Indexes down: Dow 0.25 pct, S&P 0.22 pct, Nasdaq 0.15 pct (Adds details, comments, updates prices)

By Yashaswini Swamynathan

Jan 19 (Reuters) - U.S. stocks edged lower on Thursday as investors appeared wary of taking on too much risk ahead of Donald Trump's swearing-in as president on Friday.

The markets are also digesting a clutch of information including the European Central Bank's decision to maintain its monetary policy, while awaiting a speech by Federal Reserve Chair Janet Yellen.

After hitting a series of record highs in a post-election rally, Wall Street has been trading in a tight range as investors look for more details on Trump's policies.

The S&P 500 has not moved more than 1 percent in either direction since Dec. 7.

Traders in the options market have grown increasingly cautious and have been loading up on defensive contracts, even as overall levels of stock market volatility are close to record lows.

"We may give Trump the benefit of doubt in the first hundred days but unless we see some legislation being passed through Congress, this hype might turn into gripe and that ends up being a trigger for the digestion of gains," said Sam Stovall, chief investment strategist at CFRA Research.

At 11:04 a.m. ET (1604 GMT), the Dow Jones Industrial Average was down 49.21 points, or 0.25 percent, at 19,755.51. The S&P 500 was down 4.96 points, or 0.22 percent, at 2,266.93 and the Nasdaq Composite was down 8.42 points, or 0.15 percent, at 5,547.24.

Yellen said on Wednesday the U.S. economy was getting closer to running on its own and that it made sense to raise interest rates gradually. She will speak on monetary policy at Stanford University at 8:00 p.m. ET.

Investors have been worried that Trump's pro-growth policy proposals may boost inflation, forcing the central bank to increase the pace of rate hikes.

Adding to a recent spate of robust economic data was a report that indicated U.S. homebuilding rebounded more than expected in December. Another report showed weekly jobless claims fell to a 43-year low.

Nine of the 11 major S&P sectors were lower, with declines in energy, healthcare and financials weighing on the broader index.

Exxon was off 1.5 percent following a UBS downgrade to "sell". Merck's 0.9 percent loss weighed the most on healthcare stocks.

Railroad provider CSX Corp jumped 17 percent after a source said CP Rail CEO Hunter Harrison, who steps down on Jan. 31, is in advanced talks to team up with a former Pershing Square Capital partner to shake up CSX.

Union Pacific was up 2.7 percent at $106.61 after the company reported a better-than-expected quarterly net profit.

Declining issues outnumbered advancers on the NYSE by 2,125 to 685. On the Nasdaq, 1,878 issues fell and 795 advanced.

The S&P 500 index showed 12 new 52-week highs and no new lows, while the Nasdaq recorded 50 new highs and 16 new lows.

(Reporting by Yashaswini Swamynathan in Bengaluru; Editing by Anil D'Silva)