* ECB leaves rates unchanged; inflation to stay below target
* U.S. 3rd-quarter growth revised up, jobless claims fall
* Norwegian crown hits four-year low versus euro
NEW YORK, Dec 5 (Reuters) - The euro rose to a five-week high against the dollar on Thursday after the European Central Bank left a key interest rate unchanged and its president Mario Draghi downplayed deflation risks.
The ECB decision overshadowed stronger-than-expected data on U.S. third-quarter growth and weekly jobless claims, which briefly lifted the dollar across the board.
The ECB held its key interest rate at 0.25 percent at its last policy meeting of the year, choosing not to follow through on November's surprise cut. Draghi did say the euro zone could experience a "prolonged period of low inflation," but did not highlight its downside.
"The market wanted to see a little more worry about the threat of deflation. We just got two prints that were below 1 percent," said Thierry Albert Wizeman, global interest rate and currencies strategist at Macquarie Limited in New York
"And when the market didn't see that, there was a little more covering of euro shorts."
Fresh forecasts from ECB staff predicted inflation would average just 1.1 percent next year and 1.3 percent in 2015 - well below the ECB's target of close to but below 2 percent.
The euro rose 0.5 percent to $1.3663, having climbed as high as $1.3674, according to Reuters data, the strongest since the end of October.
The euro zone currency also gained versus the British pound, rising 0.9 percent to 83.66 pence.
Draghi also said the ECB is ready to take fresh policy action to support the euro, but Macquarie's Wizeman said it is unclear what that action will involve.
"For now, it still seems that new interest-rate based measures, including acting on the ECB deposit rate, are least likely," said Wizeman.
In the United States, the economy grew faster than initially estimated in the third quarter as businesses aggressively accumulated stock, while initial claims for state unemployment benefits dropped 23,000 to a seasonally-adjusted 298,000 last week, data showed on Thursday.
The dollar briefly pared losses against the yen and hit a session high against the euro after the data.
It was last down 0.6 percent at 101.70 yen as losses in stocks boosted the safe-haven Japanese currency. Investors often flock to the yen in times of market stress.
Samarjit Shankar, director of market strategy at BNY Mellon in Boston, said the latest U.S. data have painted a picture of a stronger-than-expected economy and labor market.
"Not surprisingly, this has rekindled expectations of (Fed) tapering and market participants have chosen to take some money off the table from their risk-on trades ahead of the pivotal non-farm payrolls report due tomorrow," Shankar said.
The government is expected to report that nonfarm payrolls increased 180,000 last month and the unemployment rate fell to 7.2 percent from 7.3 percent, according to a Reuters survey of economists.
The dollar index, which measures the greenback versus a basket of six currencies, fell 0.4 percent to 80.293.
The Norwegian crown fell to a four-year low against the euro after Norway's central bank pushed back the first interest rate hike by a year.