* Euro gains erode after reaching fresh four-month high
* Dollar's safe-haven status trumped by rate differentials
* Moody's cuts Greece rating
(Recasts, adds quotes, updates prices, changes byline)
By Julie Haviv
NEW YORK, March 7 (Reuters) - The euro's recent rally against the dollar halted on Monday as sovereign debt worries returned but oil prices and expectations for higher euro zone interest rates should continue to favor the currency.
The euro, which early in the day rose to a fresh four-month high against the dollar above $1.40, saw its gains fade as trading in London wound down and liquidity began to dry up in New York. The euro was last at $1.3971, down 0.1 percent on the day, according to Reuters data.
The euro remains up about 4.3 percent against the greenback year-to-date. That can largely be attributed to expectations the European Central Bank will raise rates well before the U.S. Federal Reserve. European Central Bank President Jean-Claude Trichet surprised investors on Thursday by saying euro zone interest rates may rise as early as next month.
"It's been a long time since a major (economic) power raised interest rates, so just the thought that the ECB may raise interest rates is a big deal," said Chuck Butler, president of EverBank World Markets in St. Louis. But "it should not overshadow that the euro zone debt problems could be back if there is no resolution.
"If they do not do something by the end of March, the euro could pull back," Butler said.
Sovereign debt concerns, which have been largely dormant in recent months, moved back to the forefront with Moody's slashing Greece's debt rating by three notches. The ratings agency also kept Greek debt on review for a further possible downgrade. For more, see:.
Many economies in the 17-nation currency bloc continue to struggle with low growth and high debt burdens.
A euro zone leaders' meeting later this week may prove to be a test of euro's resilience.
Despite ongoing geopolitical turmoil, the chance of an oil-driven jump in inflation, combined with lower U.S. interest rates have diminished the dollar's safe-haven appeal.
Vassili Serebriakov, currency strategist at Wells Fargo Bank in New York, said although relative rate expectations have been a key driver for major currencies in recent days, geopolitical jitters have not gone away.
"The dollar's safe haven support has been hard to find however, and we suspect the near-term trading environment will remain somewhat challenging for the greenback," he said.
Different interest rate expectations for the United States and the euro zone are still a factor on the side of the euro.
In an interview published on Monday, ECB Executive Board member Jose Manuel Gonzalez-Paramo said an April rate increase was possible as the central bank continues its effort to control inflation.
The ECB's stance contrasts sharply with that of the U.S. Federal Reserve which is expected to keep monetary policy loose for some time. That reflects the Fed's greater concern with the U.S. economic growth outlook than inflationary pressures.
The dollar was nearly flat against the yen at 82.24 yen. The euro was down 0.2 percent against the yen at 114.86 and was nearly unchanged at 1.2942 francs.
(Additional reporting by Nick Olivari in New York; Editing by Andrew Hay)