LONDON World shares hit a new 20-month high on Tuesday after Japan's central bank promised to pump unlimited stimulus into the country's economy to fight the threat of deflation and generate growth.
The Bank of Japan, which has been under intense political pressure to overcome deflation, hiked its inflation target to 2 percent and said that from 2014 it would adopt an open-ended commitment to buy assets.
The move surprised markets, which had expected another incremental increase in its 101 trillion yen asset-buying and lending programme, though the delay until the easing measures kick in dulled the impact and saw the yen edge higher against the dollar.
"From 2014 onwards it's positive ... (but) from now until then, they are not doing anything more aggressive to weaken the yen," said Roy Teo, an FX strategist for ABN Amro.
Equity markets, particularly in Japan, have risen strongly in the run up to Tuesday's meeting, and the confirmation of the plans was enough to lift the MSCI world index 0.15 percent to a fresh 20-month high of 352.54.
European shares, which have been testing two-year highs in recent days, saw a more subdued start as investors awaited a cue from U.S. corporate earnings figures later in the day.
London's FTSE 100, Paris's CAC-40 and Frankfurt's DAX opened between flat and down 0.1 percent, leaving the FTSEurofirst 300 down 0.1 percent.
Brent crude rose 0.3 percent to $112.07 a barrel, and gold was up 0.2 percent as the BOJ's latest easing action added to recent positive data from the United States and China, while growing confidence in the strength of China's economic recovery pushed London copper up 0.7 percent to $8,111.75 a tonne.
General market sentiment was also supported by signs of a compromise to avert a U.S. fiscal crisis.
Republican leaders in the U.S. House of Representatives have scheduled a vote on Wednesday on a nearly four-month extension of U.S. borrowing capacity, aimed at avoiding a fight over the looming federal debt ceiling.
In the European bond market, Bund futures were steady as investors eyed a new 10-year Spanish bond and waited on the ZEW investor sentiment index due at 1000 GMT for the latest gauge on the health of the euro zone's largest economy, Germany.
(Reporting by Marc Jones; Editing by Will Waterman)