(Recasts with central bank action)
By Natsuko Waki
LONDON, March 11 (Reuters) - World stocks and the dollar rallied on Tuesday while safe-haven government bonds fell after the world's central banks unveiled a plan to jointly inject liquidity into financial markets.
The move gave a shot in the arm to malfunctioning world credit markets, where trading in a broad range of securities including euro zone government bonds and U.S. municipal bonds had seized up over the past week.
Yield premiums on U.S. mortgage and agency debt fell sharply after central banks in the United States, Britain, the euro zone, Switzerland and Canada, announced the coordinated liquidity move, the first since December.
The latest pressure on money markets has partly stemmed from fears that hedge funds which are missing margin calls might be forced to sell a broad range of debt instruments to raise liquidity.
This has added to overall concerns that banks, some of which are facing billions of dollars more in writedowns, might grow even more reluctant to lend, crippling overall economic activity.
"The Fed and global central banks have provided the thing everyone needed and that's cash. The clear dislocations seen in some bond markets of late have been related to the need for cash by some financial intermediaries," said Martin Blum, head of emerging markets research at Unicredit in Vienna.
"The actions ... deal with this issue by making it easier for banks to get cash and that's important."
After the announcement, the FTSEurofirst 300 index <
> was up 2.2 percent from Monday, while MSCI main world equity index <.MIWD00000PUS> extended gains to 0.9 percent. The index earlier hit its weakest since mid-January.Wall Street started trading sharply higher <.SPX>.
FIXED INCOME MOVES
Moves were also pronounced in fixed income markets.
Benchmark 10-year U.S. Treasury prices <US10YT=RR> were down almost 100 ticks, for a yield of 3.5978 percent. The June Bund future <FGBLM8> fell in tandem with other government bonds, down 70 ticks on the day.
U.S. swap spreads narrowed, indicating a lower cost of hedge against U.S. interest rate swings. The spread on two-year interest rate swaps over Treasuries narrowed to 92.75 basis points, the tightest since late February.
In the latest round of liquidity measures, the Fed expanded a securities lending programme and will accept a broader range of securities, including U.S. agency debt and mortgage debt, as collateral. Spreads on U.S. mortgage and agency debt tightened sharply as a result.
Intra-euro zone government bond spreads -- which have been widening due to diminishing liquidity for peripheral paper and surging demand for safe German paper -- also narrowed by a few basis points.
The Fed's foreign exchange swap lines with the European Central Bank and the Swiss National Bank also increased, ensuring better dollar liquidity.
The dollar rose nearly a full yen to 102.97 <JPY=> while the euro slipped to $1.5377 <EUR=>, still up a quarter percent on the day.
The euro earlier hit a record high at nearly $1.55 <EUR=> after a survey showed German investor morale unexpectedly improved in March.
The closely-watched ZEW survey showed its economic sentiment indicator rose to a higher-than-expected -32.0 this month from -39.5 in February.
The central banks' move comes as money markets flashed warning lights again in recent sessions. The problems are also emerging in the secured type of lending that required collaterals, which had so far escaped the turmoil.
Demand for a 12-month Italian bill at an auction fell short of the offered amount of 7.5 billion euros ($11.60 billion), reflecting reluctance among investors to buy peripheral euro zone government bonds. This is the first time this happened in nine years.
Elsewhere, emerging sovereign spreads <11EMJ> tightened 15 basis points to 291 basis points while emerging stocks <.MSCIEF> rose 1.7 percent.
The iTraxx Crossover index <ITCRS5EA=GFI>, which gauges the cost of corporate bond insurance in Europe, tightened to 632 basis points, after hitting record levels last week.
U.S. light crude oil <CLc1> rose to a new all-time high around $109.48 a barrel before trimming gains. Gold <XAU=> rose 1 percent to $984.00 an ounce before falling.