GLOBAL MARKETS-Stocks jump on Japan and M&A, volatility down

* Euro above $1.42 vs USD on rate hike expectations

* Wall Street stocks boosted by AT&T's T-Mobile deal

* U.S.-traded Nikkei futures up 3.6 percent

* VIX posts largest daily drop since May (Updates prices, changes quotes)

By Rodrigo Campos

NEW YORK, March 21 (Reuters) - Stocks in major world markets rallied on Monday as the appetite for riskier assets returned following some progress in resolving Japan's nuclear plant crisis, while the yen slipped on speculation of further market intervention.

Japan's markets were closed for a holiday, but the MSCI index of Asian stocks outside of Japan <.MIAPJ0000PUS> rose 1.4 percent and U.S.-traded Nikkei futures advanced for a third session.

The yen fell on investor concerns over more coordinated actions by the world's major central banks to weaken the Japanese currency following last week's intervention by the Group of Seven.

Oil prices were higher after a second round of U.N.-mandated airstrikes on Libya and spreading protests in the Middle East reinforced concerns about potential supply disruption.

In a sign of some normalcy returning to the markets following Japan's earthquake, tsunami and nuclear plant crisis, Wall Street's so-called fear gauge posted its largest daily drop since May.

U.S. stocks were up about 1.5 percent on late Monday trading in New York as investors welcomed AT&T Inc's $39 billion offer to buy T-Mobile USA from Deutsche Telekom in what would be the world's biggest deal this year and Germany's biggest in a decade.

"The market has been really volatile and it will continue to be really volatile. The AT&T deal is just a piece of it, the other is a sense there is some better news out of Japan and things haven't gotten any worse in Africa," said Gail Dudack, chief investment strategist at Dudack Research Group in New York.

ROBOT

The third day of gains in U.S. stocks followed two weeks of losses over concerns about unrest in oil-producing North Africa and the Middle East. Japan's earthquake and tsunami and the ensuing nuclear crisis deepened investors' concerns about a continued global economic recovery.

"The effects on oil from Libya to the US are very modest, if at all. The Saudis are making up the difference (in output) so it comes down more to politics than economics in Libya," Dudack said.

The CBOE volatility index <.VIX> tumbled 15.2 percent in its largest daily percentage drop since last May.

It fell below its 14- and 200-day moving averages for the first time since the earthquake in Japan.

The FTSEurofirst 300 <.FTEU3> index of top European shares rose 1.75 percent to hit a one-week high and the MSCI world share index <.MIWD00000PUS> jumped 1.5 percent, the largest daily gain in seven weeks.

Experts said Japan's reconnection of power to its earthquake-damaged reactors is a major step in managing its nuclear crisis, but two smoking reactors and worries about food safety showed the crisis was far from over. For details, see [ID:nL3E7EL17R]

Equities got a boost after billionaire investor Warren Buffett said the earthquake and tsunami are the kind of extraordinary events that create a buying opportunity for shares in Japanese companies. [ID:nTOE72I00I]

U.S. dollar-denominated Nikkei futures rose 3.6 percent and have gained roughly 11 percent in the last three sessions.

YEN SLIPS, EURO HITS 4-MONTH HIGH

The yen added to losses, with speculators wary of more coordinated actions by top central banks after joint G7 intervention last week hoisted the greenback nearly 4.0 percent versus the Japanese currency. The U.S. dollar rose 0.2 percent for the day to 80.97 yen .

The euro rose 0.3 percent above $1.42 against the U.S. dollar for the first time since November as markets braced for a euro zone interest rate hike as soon as next month.

A measure of the greenback against a basket of major currencies fell to its lowest in 15 months.

Libya Graphics

http://link.reuters.com/neg68r

Japan disaster in figures

http://r.reuters.com/ser58r

Japan disaster Top News page

[nTOPNOW4]

Picture, graphic packages:

http://r.reuters.com/wyb58r

OIL PRICES FIRMER

Brent crude for May delivery was up more than 90 cents at $114.86 a barrel after the attacks on Libya, aimed at protecting civilians caught up in a revolt against the nation's leader, Muammar Gaddafi. [ID:nLDE72K0F1]

Brent has risen nearly 22 percent this quarter, with prices buoyed by uncertainty over the unrest in North Africa and the oil-producing Gulf region.

Oil traders have been also following Japan's crisis closely.

"Concerns about demand in Japan were raised when smoke started coming from one of the reactors, pulling crude off the early highs. It's negative psychology for the market," said Phil Flynn, analyst at PFGBest Research in Chicago.

U.S. Treasuries prices were hurt by reduced safe-haven demand and extended losses after the Treasury said it will begin to sell $142 billion of its agency-guaranteed mortgage-backed securities. [ID:nN21219886]

Benchmark 10-year notes were last down 14/32 in price to yield 3.32 percent, up from 3.28 percent late Friday.
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(Additional reporting by Wanfeng Zhou, Chuck Mikolajczak, Karen Brettell, Robert Gibbons and Alejandro Barbajosa; Editing by Andrew Hay)