(Updates prices, adds economic surprise indices)
* Dollar index hits 11 1/2-year peak
* Euro support fails at $1.1150
* Gains in U.S. bond yields support dollar
* Surprise indices favour euro zone in past month
By Patrick Graham
LONDON, March 4 (Reuters) - The euro crashed through support levels that had held for more than a month on Wednesday, hitting a six-week low under pressure from the imminent launch of outright quantitative easing by the European Central Bank.
The dollar, bolstered by recent rises in U.S. government bond yields, hit its highest since September 2003 against the basket of currencies used to measure its broader strength.
There has been more momentum behind the greenback in the past week after a month of mediocre data which had left it struggling to build on six months of gains against all of its major currency peers.
Dealers said further progress against the euro on Wednesday was likely to depend more on a rash of U.S. sentiment data due later in the session than the ECB’s policy meeting on Thursday.
“Its really the dollar side of the equation that is at stake at the moment,” said Daragh Maher, a strategist with HSBC in London. “The ECB has told us what it is going to do so in that sense the euro is on autopilot; it is hard for the (European) data to change anything.”
By 1200 GMT the euro was down 0.4 percent at $1.1129, having dropped to $1.1115 earlier in the session. The dollar index was up by a third of a percent at 95.761..
Other moves saw the Swedish crown rise to a three month high of 9.2080, adding to gains in the previous day after deputy central bank governor Kerstin af Jochnick said there was a risk of crown gains due to the ECB’s planned QE scheme.
The crown, though, was lower against the dollar at 8.2760.
The dollar index has gained about 5.7 percent so far this year, helped by the U.S. economy’s better performance against other major world economic regions and relatively higher U.S. yields.
Its rise has slowed over the past month or so, however, as investors have seen fewer catalysts to move the dollar higher given the uncertainty over whether the U.S. Federal Reserve will start raising interest rates by mid-year or wait a while longer.
Economic data surprise indices run by HSBC and Citi both show euro zone data beating expectations more often while U.S. numbers do the opposite - one possible reason for the dollar’s failure to take off in February.
Against the yen, the greenback was just 0.1 percent lower at 119.63 yen, down from Tuesday’s almost three-week high of 120.27 yen.
The Australian dollar got a slight lift as the market took comfort in data showing the economy grew as expected last quarter, when the risk had been for a softer outcome.
The Aussie dollar traded close to an intraday high of $0.7838, up 0.2 percent on the day.
“Australian GDP data were a bit softer than expected but that was due to inventories and not a reason for fresh bearishness,” said Kit Juckes, a strategist with Societe Generale in London. (Additional reporting by Francesco Canepa and Anirban Nag; Editing by Toby Chopra)