* AT&T to buy T-Mobile USA from Deutsche Telekom
* Oil rises after Western powers attack Libya
* Buffett: Japan quake is "buying opportunity" in stocks
* Futures up: S&P 15 pts, Dow 117 pts, Nasdaq 26 pts
* For up-to-the-minute market news see [STXNEWS/US] (Adds byline, quote)
By Angela Moon
NEW YORK, March 21 (Reuters) - Wall Street stock indexes were poised to rise more than 1 percent at the open on Monday as investors welcomed AT&T's proposal to buy T-Mobile from Deutsche Telekom.
Glimmers of hope about Japan's nuclear crisis and investor Warren Buffett's comments about a buying opportunity for Japanese stocks also boosted investor sentiment.
A&T Inc (T.N) said it would pay $39 billion for Deutsche Telekom AG's (DTEGn.DE) T-Mobile USA, sparking a sharp rally in European telecom shares. For details, see [ID:nN20237333]
AT&T shares were up 1.5 percent at $28.36 in premarket trade. In European market, Deutsche Telecom rose 13 percent and Vodafone Plc (VOD.L) was up 4.4 percent.
But competitor Sprint Nextel Corp (S.N) shares were down 13 percent to $4.39 before the bell.
Investors kept a close eye on events in Japan, where power cables have been connected to all six nuclear reactors at the Fukushima Daiichi power plant damaged by an earthquake and tsunami. The World Health Organization said radiation found in food from the area near the damaged nuclear plant was a "serious situation." [ID:nL3E7EK08V]
The market also closely followed Libya, where Western powers launched a second wave of air strikes early Monday after halting the advance of Muammar Gaddafi's forces on Benghazi and targeting air defenses in the country. Brent crude oil futures for May LCOc1 jumped $1.94 to $115.87 a barrel.
"Instead of 'shock and awe,' it seems what we're seeing in Libya is more 'hit and run.' I say this because without ground troops going in to physically remove Gaddafi, it's not clear how this ends, and while stock markets globally are higher this morning, we've also gotten higher oil prices in addition to a reprieve for the rebels," said Peter Boockvar, equity strategist at Miller Tabak and Co in New York.
Warren Buffett said Japan's devastating earthquake is the kind of extraordinary event that creates a buying opportunity for shares in Japanese companies. He spoke during a visit to a South Korean factory run by a company owned by one of his funds. [ID:nTOE72I00I]
S&P 500 futures SPc1 rose 15 points and were above fair value, a formula that evaluates pricing by taking into account interest rates, dividends and time to expiration on the contract. Dow Jones industrial average futures DJc1 jumped 117 points, and Nasdaq 100 futures NDc1 put on 26 points.
European stocks .FTEU3 were up 1.6 percent early Monday. Japanese markets were closed for a holiday.
Data on U.S. existing home sales is due at 10:00 a.m. (1400 GMT). Economists in a Reuters survey predict a rate of 5.15 million annual units for February, down from 5.36 million in the previous month.
U.S. stocks gained Friday after a week of volatility, but investors were reluctant to make big bets due to turmoil in the Middle East and Japan's nuclear crisis. (Editing by Padraic Cassidy)