* Euro falls versus dollar and yen after ECB's Draghi comments

* January retail sales beat expectations, but worries remain

* Greenlight's Einhorn sues Apple, seeks bigger payout; Apple shares up

* Indexes: Dow off 0.7 pct, S&P off 0.6 pct, Nasdaq off 0.7 pct

By Angela Moon

NEW YORK, Feb 7 (Reuters) - U.S. shares fell on Thursday after the euro currency dropped against the safe-haven dollar and yen, raising worries about Europe's outlook and curbing investors' appetite for risky assets, such as stocks.

The euro sank against the dollar and yen after European Central Bank President Mario Draghi said the exchange rate was important to growth and price stability, which investors took as a sign the bank is concerned about the euro's advance in recent days.

U.S. stocks have been in an uninterrupted uptrend for most of the year, with the S&P 500 gaining more than 5 percent for the year.

"The market is a bit shaky on the back of some of the Draghi comments" amid worry the strength of the euro might hamper economic recovery, said Andre Bakhos, director of market analytics at LEK Securities in New York.

"Whether this ignites renewed concerns about the euro debt struggles and Europe in general is yet to be seen, but the market is looking for any reason to take a profit. It is just consolidating near multiyear highs, taking a respite before we advance higher."

The Dow Jones industrial average was down 97.57 points, or 0.70 percent, at 13,888.95. The Standard & Poor's 500 Index was down 9.62 points, or 0.64 percent, at 1,502.50. The Nasdaq Composite Index was down 23.22 points, or 0.73 percent, at 3,145.26.

Housing and retail stocks were the day's biggest decliners. The housing sector index was off 1.5 percent and the S&P housing index was off 0.9 percent.

Top U.S. retailers reported strong January sales after offering compelling merchandise that drew in shoppers facing a hit to their take-home pay from higher payroll taxes.

Macy's Inc rose 1.1 percent to $39.94 after reporting January same store sales rose 11.7 percent.

But Ann Inc dropped 7.1 percent to $30.48 after forecasting fourth-quarter sales below analysts' expectations.

Fund manager David Einhorn's Greenlight Capital on Thursday said it has sued Apple Inc and said the company needs to do more to unlock value for shareholders. Apple shares gained 0.2 percent to $455.73 after rising about 1 percent earlier.

Akami Technologies Inc lost 16.4 percent to $34.78 as the worst performer on the S&P 500 after the Internet content delivery company forecast current-quarter revenue below analysts' expectations.

Weekly initial jobless claims dipped last week, with the four-week moving average falling to its lowest level since March 2008, signaling the economy continues to recover slowly.

A separate report said fourth-quarter productivity registered its biggest drop in nearly two years, while unit labor costs jumped 4.5 percent, more than economists expected.

According to Thomson Reuters data through Thursday morning, of 317 companies in the S&P 500 that have reported earnings, 69 percent have exceeded analysts' expectations, above a 62 percent average since 1994 and 65 percent over the past four quarters.

Fourth-quarter earnings for S&P 500 companies rose 5 percent, according to the data, above a 1.9 percent forecast at the start of the earnings season.