By Karen Brettell

The euro jumped to a 12-week high against the U.S. dollar on Thursday after the European Central Bank increased stimulus to shore up economies hurt by the coronavirus pandemic.

The ECB increased the size of its Pandemic Emergency Purchase Program (PEPP) to 1.35 trillion euros ($1.52 trillion) from 750 billion euros, more than the 500 billion-euro increase most analysts had expected, and extended it until June 2021 at the earliest, with a pledge to reinvest proceeds until at least the end of 2022.

"This highlights the ECB's commitment to strengthening the recovery," said Jai Malhi, global market strategist at J.P. Morgan Asset Management in London. "The euro zone may well emerge from the COVID-19 recession more quickly than the U.S. and UK."

The single currency gained 1.04% to $1.1349, after earlier reaching $1.1361, the highest since March 11. It has gained for eight consecutive sessions.

The dollar index <=USD>, which measures the greenback against a basket of major currencies, fell 0.67% to 97.675.

The dollar has declined for the past two weeks as risk sentiment improves and stocks jump on optimism that the worst of the economic downturn from the coronavirus has passed.

The stock rally appeared to run out of steam on Thursday, however, with Wall Street trading lower ahead of Friday's jobs report.

U.S. data on Thursday showed that the number of Americans filing for unemployment benefits dropped below 2 million last week for the first time since mid-March, but remains astonishingly high as companies adjust to an environment that has been significantly changed by COVID-19.

The dollar gained 0.20% against the safe-haven Japanese yen to 109.11 yen, after earlier rising to 109.16, the highest since April 7.

The Australian dollar, which has been one of the best recent performers due to the increase in risk appetite, rose 0.26% to $0.6937, after getting as high as $0.6987, the strongest since Jan. 3.

Sterling gained 0.31% to $1.2611, after earlier reaching $1.2633, the highest since April 30.

The Hong Kong dollar rose to 7.75 per U.S. dollar, the strong end of its trading band, for the first time since May 21.

(Reporting by Karen Brettell; Editing by Bernadette Baum)