* G20 in $1 trillion deal to stave off recession

* Regulator relaxes accounting rules for banks

* Factory orders rise in February

* Dow up 2.8 pct, S&P up 2.9 pct, Nasdaq gains 3.3 pct

* For up-to-the-minute market news click [STXNEWS/US] (Updates with Research in Motion's results after the bell, adds context on indexes in paragraph 2, plus latest Nasdaq volume )

By Edward Krudy

NEW YORK, April 2 (Reuters) - U.S stocks rallied for a third day on Thursday as more data pointed to a stabilizing economy and changes to an accounting rule were seen as shoring up the volatile financial sector in the short term.

World leaders at the G20 summit on London also boosted markets when they announced an additional trillion dollars to support the International Monetary Fund and boost flagging trade. For more details see [ID:nL1230573].

Stocks have surged in recent sessions as data increasingly point to an easing in the deep recession. The Dow is now on track for its best four-week rally since 1933. Both the blue-chip Dow average and the S&P 500 ended Thursday's session at nearly two-month highs.