* Dollar index hits peak last seen in 2003

* Euro sinks below $ 1.11 to new low

* U.S. private jobs data seen positive for Friday payrolls report (Adds late prices, details)

By Michael Connor

NEW YORK, March 4 (Reuters) – The dollar climbed to a fresh 11-1/2-year high on Wednesday, boosted by strong U.S. private-sector jobs growth ahead of the launch of quantitative easing by the European Central Bank.

The dollar hit its highest since September 2003 against a basket of currencies and was last up 0.6 percent at 95.958. Earlier it struck a high of 96.059.

The ADP National Employment Report showed a gain of 212,000 private-sector jobs. Economists surveyed by Reuters had forecast the ADP to show a gain of 220,000 jobs.

Separately, the Institute for Supply Management said its services index was 56.9 in February, up slightly from 56.7 in January. Analysts were looking for a reading of 56.5 for the sector that makes up the bulk of the U.S. economy, according to a Reuters poll.

The ADP data signals strength in Friday’s potentially market-moving U.S. jobs report for February, according to Camilla Sutton, chief currency strategist at Scotiabank in Toronto.

“What’s really important now is that we get a nonfarm print on Friday that comes close to that 235,000 that is expected, or higher,” Sutton said. “That will keep the expectations for a Fed interest rate hike fairly near term. For the U.S. dollar that is key.”

The euro’s low was its lowest level against the dollar since September 2003. It last stood at $ 1.1071, off 0.92 percent for the day and below a key support level, Sutton said.

The euro also declined to one-month lows against the yen , which was flat against the dollar at 119.72 yen. Sterling was off 0.7 percent to $ 1.5259.

The ECB is expected to announce details of its planned 1.1 trillion euro bond-buying program on Thursday, meant to spur European economies as the Fed readies to raise rates for the first time since 2006.

The dollar index has gained about 6.3 percent so far this year, helped by the U.S. economy’s better performance against other major economic regions and relatively higher U.S. yields.

(Additional reporting by Francesco Canepa and Anirban Nag in London; Editing by Christian Plumb and James Dalgleish)