* World stocks, commodities, oil rise after U.S. Fed's move
* European leaders resist US calls for more spending
* Fed to buy $300 bln of Treasuries, $850 bln mortgage bonds
* Japan finmin welcomes help from BOJ bond buying
(Adds Merkel, British deficit, S&P forecast, updates markets)
By Mark Felsenthal and Philippa Fletcher
WASHINGTON/LONDON, March 19 (Reuters) - A surprise injection of an extra $1 trillion into the U.S. economy by the Federal Reserve lifted global economic sentiment on Thursday but European leaders looked set to resist pressure to spend more.
"A competition to outdo each other with promises will not calm the situation," German Chancellor Angela Merkel said in a speech to the Bundestag lower house of parliament before heading to a European Union summit in Brussels.
Washington, where U.S. jobless claims data hit another record on Thursday, has urged European leaders to put more cash into their struggling economies to reverse a global recessionary spiral.
Europe's unemployment rate could near 10 percent by the end of this year and mass protests by unions in France on Thursday underlined the social impact of the economic woes.
But leaders were expected to suggest April's G20 talks focus on tightening regulation and giving the International Monetary Fund more firepower rather than further state spending.
"Some of us have not yet implemented our national recovery plans, so we don't know their impact. It does not make sense to introduce new packages," Czech Prime Minister Mirek Topolanek, whose country holds the rotating EU presidency, told reporters.
The Fed announced it would buy up to $300 billion of longer term U.S. government debt over the next six months on Wednesday in the first operation on such a scale since the 1960s.
It also pledged to expand a scheme to buy mortgage-related securities by $850 billion, to $1.45 trillion this year, driving U.S. home mortgage rates towards record lows.
Few analysts had expected the U.S. to follow Japan and Britain in pumping money directly into the economy so soon.
Investors shunned the dollar in favour of riskier markets like commodities and oil while bank shares led a rise in global stock markets that signalled cautious optimism.
"Whilst it is too early to say that the green shoots of recovery are here, the pendulum appears to be swinging back to half way," said Chris Hossain, senior sales manager at ODL Securities.
He and others stressed that initial euphoria could soon peter out if lending did not revive.
BORROWING PROBLEMS
"Will the next trillion dollar injection gain any more traction? Probably not. Banks don't want to lend and borrowers don't want to borrow," economists at DBS Bank in Singapore said in a note, stressing that fixing the ailing banks was necessary for recovery to take hold.
The Fed's announcement came hours after the Bank of Japan boosted its government bond purchases plan for this year by nearly a third to 21.6 trillion yen ($225 billion).
Days before that the Bank of England started buying government bonds with newly created money to breathe life into the faltering British economy.
All three central banks have already pushed interest rates near to zero and are looking for unorthodox ways of getting funds flowing to companies and consumers to battle the worst global downturn since the 1930s Great Depression.
A leading Chinese government think-tank recommended depreciation of the yuan currency in the face of a weak outlook for China's industrial output growth and flagging exports.
The European Central Bank, for its part, is short of room to manoeuvre as individual members of the eurozone do not seem equally equipped to resist damaging deflationary pressures, Standard and Poor's rating agency said.
"While Germany, France or even Italy seem immune to a deflationary spiral, the same cannot be said of Ireland or Spain, where the recession is likely to drag on for a longer period of time," it said.
Of all major economies, Japan has been hit hardest by the collapse in global demand and trade.
A monthly Reuters survey of Japanese manufacturers confirmed the dire state of the world's No.2 economy on Thursday, with its sentiment gauge hitting a record low in March.
Prime Minister Taro Aso, faced with approval ratings near 10 percent and the worst recession since World War Two, is planning a third stimulus package.
Britain posted its biggest February budget deficit on record, taking the total for the fiscal year so far to 75.2 billion pounds, the highest since comparable records began in 1993.
"The fiscal outlook is pretty awful and it is going to take a long, long time to repair it," said Ross Walker, economist at Royal Bank of Scotland. (Reporting by Reuters bureaux worldwide; writing by Philippa Fletcher; editing by Jon Boyle)