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* Dollar index close to last week's highs
* Investors seen lightening positions into year-end
* Yen boosted by better-than-expected Japanese data
* Graphic: World FX rates in 2016 tmsnrt.rs/2egbfVh
By Jemima Kelly
LONDON, Dec 19 (Reuters) - The dollar steadied close to its highest levels in 14 years on Monday, underpinned by expectations that a fiscal expansion planned by U.S. President-elect Donald Trump will boost inflation and lead to a faster pace of interest rates hikes.
The greenback surged to its highest since January 2003 against a basket of currencies last week and threatened parity with the euro, after the U.S. Federal Reserve hinted that rates could rise as many as three times next year.
But the dollar drifted a little on Friday and, at 102.88 on Monday, was around 0.7 percent below Thursday's peak of 103.56, with investors booking profits and lightening hefty bets on the currency as a two-week holiday period began, meaning thin liquidity.
"The strength we've had post Trump's election could fade a little into the end of the year. People just close down some of their long positions on the dollar," said HSBC currency strategist Dominic Bunning, in London.
"Does the market still believe in the Trumpflation story? Does it still believe Trump is going to deliver fiscal loosening, with infrastructure spending, tax cuts etc? At the moment there's been nothing to change that view."
Citi's head of G10 currency strategy in London, Richard Cochinos, said a speech by Fed Chair Janet Yellen due at 1830 GMT would be watched for any hint that last week's Fed meeting was interpreted by markets as more hawkish than had been intended.
Against the yen, the dollar fell as much as 0.9 percent, before recovering a touch to trade down half a percent on the day by 1140 GMT at 117.27 yen. The yen was boosted by data showing Japan's export performance improved strongly in November.
Data released on Friday showed dollar net long positions were little changed in the week to Dec. 13, affirming a trend in place since the Trump's election victory on Nov. 8. Net shorts on the yen rose to their largest since early December last year.
The Bank of Japan kicked off a two-day policy meeting on Monday, at which it is expected to maintain its 10-year government bond yield target as the weaker yen helps Japan's economic prospects, a Reuters poll showed on Friday.
"The speed of the yen's weakening was likely much faster than the BOJ anticipated," said Ayako Sera, market economist at Sumitomo Mitsui Trust Bank in Tokyo.
"While no major changes are expected from the meeting, some tweaks to policy are possible, to adjust to the new market situation," she said.
For Reuters new Live Markets blog on European and UK stock markets see reuters://realtime/verb=Open/url=http://emea1.apps.cp.extranet.thomsonreuters.biz/cms/?pageId=livemarkets (Additional reporting by Tokyo markets team; editing by John Stonestreet)