* Dollar index rises but is still near 15-month low
* Weak dollar trend to persist, analysts say
* Pound falls after Fitch warns on UK rating
* Euro struggles to hold above $1.50 (Updates prices, adds detail)
By Steven C. Johnson
NEW YORK, Nov 10 (Reuters) - The dollar bounced off a 15-month low on Tuesday and the euro dipped below $1.50 as investors paused to assess whether the global outlook justifies a recent rally in higher-yielding currencies and assets.
U.S. stock indexes were mixed as investors moved to the sidelines, providing respite for the dollar, which investors borrow at low rates to fund purchases of higher-yield assets.
Sterling tumbled after Fitch ratings agency told Reuters that Britain was the economy most at risk of losing its top AAA credit rating, though the pound later recouped most losses.
Analysts said the dollar was still out of favor, though, as investors expect benchmark U.S. interest rates to remain near zero into 2010 as the economy recovers from a harsh recession.
"With many currencies reaching new highs recently, there is a reasonable amount of resistance toward a headlong lunge into fresh territory for now," said Andrew Wilkinson, senior analyst at Interactive Brokers Group in Greenwich, Connecticut.
John Doyle, foreign exchange strategist at Washington-based Tempus Consulting, added, "yesterday, we might have moved a little too far too quickly."
The euro dipped 0.1 percent to $1.4978, off its 2009 high above $1.5060. It hit $1.5020 earlier. The dollar was down 0.2 percent at 89.85 yen while the euro fell 0.3 percent to 134.56 yen.
An index of the dollar against six major currencies edged up 0.01 percent after hitting a 15-month low on Monday.
The euro wobbled after a German ZEW economic sentiment index showed that investors were more gloomy than at any time in the last four months.
Sterling fell after Fitch Ratings said that of the four major economies with top-notch AAA status, the UK was the most at risk. That pushed the currency to $1.6602, nearly two cents off its session high, though it had ground its way back to $1.6729, down 0.1 percent, by late afternoon in New York.
David Riley, co-head of global sovereign ratings at Fitch, said if there was another significant fiscal stimulus package in highly indebted Britain its rating would be at risk.
"The Fitch news was a reminder of the longer-term issues facing the UK," said Lutz Karpowitz, currency strategist at Commerzbank in Frankfurt.
Still, with U.S. interest rates expected to remain low, analysts said they saw little traction for the dollar, and several Federal Reserve officials on Tuesday struck a cautious note on the U.S. economic outlook. (Additional reporting by Nick Olivari; Editing by James Dalgleish)