* Yellen's speech at 12:45 p.m. ET
* Equifax down after CEO resigns
* Apple biggest boost to three major indexes
* Indexes up: Dow 0.29 pct, S&P 0.25 pct, Nasdaq up 0.49 pts (Updates to open)
By Sruthi Shankar
Sept 26 (Reuters) - A bounce in tech stocks, led by Apple and Nvidia, lifted the three major indexes on Tuesday.
Apple rose 1.31 percent, a day after it flirted with correction territory following a report that the company had told suppliers to scale back shipments of parts for its upcoming iPhone X.
Nvidia was up more than 4 percent, following a launch of an artificial intelligence-related software product.
Technology stocks had taken a beating on Monday, sliding to their worst daily performance in five weeks, on increasing worries that the top-performing sector was falling out of favor.
Investors are awaiting Fed Chair Janet Yellen's speech later in the day for clues on interest rates.
However, concerns lingered over escalating tensions between the United States and North Korea.
The Korean peninsula appears to have boosted defenses on its east coast, according to a South Korean lawmaker, after Pyongyang said President Donald Trump had declared war and that it would shoot down U.S. bombers flying near the peninsula.
At 9:37 a.m. ET (1337 GMT), the Dow Jones Industrial Average was up 65.45 points, or 0.29 percent, at 22,361.54, the S&P 500 was up 6.34 points, or 0.25 percent, at 2,503 and the Nasdaq Composite was up 30.99 points, or 0.49 percent, at 6,401.58.
Six of the 11 major S&P sectors were higher, with a 0.62 percent gain in the technology sector topping the list.
Energy index though was among the biggest laggards, falling 0.39 percent.
Among stocks, credit reporting firm Equifax fell 1.30 percent after the company said its Chief Executive Richard Smith would retire, in the wake of a massive cyber attack.
Red Hat rose 4.56 percent after the Linux distributor's quarterly profit came in above estimates and the company raised its full-year forecast.
Cleveland Fed Chief Loretta Mester, her Atlanta counterpart, Raphael Bostic, and Fed's Board Governor Lael Brainard are also scheduled to speak later in the day.
Advancing issues outnumbered decliners on the NYSE by 1,585 to 913. On the Nasdaq, 1,448 issues rose and 804 fell. (Reporting by Sruthi Shankar in Bengaluru; Editing by Anil D'Silva)