* Dollar index falls as Yellen remarks suggest dovish bent
Ruble recovers losses as Ukraine news turns more positive
* Yen, Swiss franc gain on worries over emerging markets
By Sam Forgione
NEW YORK, Feb 27 (Reuters) - The dollar fell on Thursday against a basket of major currencies after comments by Federal Reserve Chair Janet Yellen suggested the U.S. central bank could maintain its easy monetary policies for longer than expected.
Yellen, in comments before the Senate Banking Committee, failed to provide clarity on the impact of a harsh winter on recent economic weakness and reiterated concerns about the state of the U.S. labor market.
"The dollar reversed it's earlier bullish course and moved back lower after traders interpreted Yellen's comments as being a bit more dovish," said Greg Michalowski, chief currency analyst at FXDD in Phoenix.
Traders said the Fed could delay reductions to its monthly bond-buying program and keep interest rates low for longer if it attributed recent weak U.S. economic data to a broader economic slowdown rather than cold weather.
An expectation of prolonged easy-money policies hurts the dollar because lower interest rates deter capital flows into the United States.
The yen and the Swiss franc rose on jitters over the possibility of Russian intervention in Ukraine, adding to concerns about emerging markets and driving capital into the world's traditional safe-haven currencies.
The Russian ruble hit a five-year low against the dollar on Thursday, as tensions escalated in Ukraine after Russian President Vladimir Putin ordered drills by his armed forces to test combat readiness in western Russia, near the border with Ukraine. The dollar rose against the ruble to 36.2670, the highest level since February 2009, but then pared gains to trade mostly flat against the ruble on more positive news on Ukraine.
The greenback last traded against the ruble at 36.0125. The International Monetary Fund said it would send a fact-finding team to Ukraine next week in response to Kiev's request for support after the ouster of President Viktor Yanukovich, which helped the ruble recover losses.
"It's a little bit of a turn in sentiment," said Win Thin, global head of emerging markets strategy at Brown Brothers Harriman in New York.
Even so, in another sign of the tensions in Russia and Ukraine, the dollar was last up 5 percent against Ukraine's hryvnia, hitting a record high of 10.6 hryvnia.
The dollar index, which tracks the U.S. dollar against a basket of major currencies, was last down 0.14 percent at 80.313, a day after holding near a two-week high.
The dollar was down against the euro, which last traded up 0.14 percent at $1.3706. The dollar was down 0.25 percent against the yen, at 102.09, and was last down 0.23 percent against the Swiss franc, which traded at 0.88855.
Traders largely shrugged off Labor Department data showing initial claims for U.S. unemployment benefits increased 14,000 last week to a seasonally adjusted 348,000.
Other reports showed orders for long-lasting U.S. manufactured goods excluding transportation unexpectedly rose last month, as did a gauge of business spending plans. Both had little effect on the dollar.
The dollar last traded mostly flat against the Chinese yuan, which has had its most severe fall in years. Traders have said that the People's Bank of China has engineered the drop, but that it also reflects worries that the Chinese economy, which has propped up global growth for a decade, is stuttering.
The dollar was last at 6.1284 versus the yuan.