* U.S. stocks soar on AT&T's T-Mobile deal
* U.S.-traded Nikkei futures advance
* VIX posts largest daily drop since May
* Euro touches $1.42 vs USD on rate hike expectations (Updates prices, adds VIX, 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.
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 slightly higher after a second round of U.N.-mandated airstrikes on Libya and after spreading protests in the Middle East reinforced concerns about potential supply disruption.
In a sign of some normalcy returning to the markets following the Japanese earthquake, tsunami and nuclear plant crisis, Wall Street's fear gauge posted its largest daily drop since May.
U.S. stocks were up about 1.5 percent on Monday afternoon
in New York as investors welcomed AT&T Inc's
The Dow Jones industrial average <.DJI> was up 186.78 points, or 1.58 percent, at 12,045.30. The Standard & Poor's 500 Index <.SPX> was up 19.54 points, or 1.53 percent, at 1,298.74.
"Any sort of M&A activity has a beneficial impact on the market as a whole because it gives the impression corporate insiders see value in the market," said Thomas Villalta, portfolio manager for Jones Villalta Asset Management in Austin, Texas, which he said has a small holding in telecom services.
The gains in U.S. stocks for a third day 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.
"More incrementally positive news from Japan in terms of the nuclear situation is helping the market," said John Canally, investment strategist at LPL Financial in Boston.
The CBOE volatility index <.VIX> tumbled 15.8 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 1.7 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
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
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
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
http://blogs.reuters.com/globalinvesting
* For the MacroScope blog http://blogs.reuters.com/macroscope
* For hedge fund blog http://blogs.reuters.com/hedgehub
(Additional reporting by Wanfeng Zhou, Caroline Valetkevitch,
Karen Brettell, Robert Gibbons and Alejandro Barbajosa)