* Buffett's Berkshire rises after strong results
* PepsiCo up as CEO Indra Nooyi to step down
* Intel down after Barclays downgrade
* Futures down: Dow 12 pts, S&P 1.25 pts, Nasdaq 6 pts (Adds comment, details; updates prices,)
By Sruthi Shankar
Aug 6 (Reuters) - U.S. stock indexes were on track to open slightly lower on Monday as investors focused on escalating trade tensions between the United States and China.
China proposed a set of differentiated tariffs on $60 billion worth of U.S. imports last week, retaliating to the Trump administration's plans of 25 percent tariffs on $200 billion worth of Chinese imports.
Chinese state media launched a personal attack on President Donald Trump's trade policies on Monday, saying his trade "extortion" would not work.
The months-long dispute has roiled financial markets across the globe, although the U.S. markets have been largely supported by a strong earnings season.
Of the more than 400 S&P 500 companies that have reported so far, 78.6 percent have topped earnings estimates. That is well above the average of 72 percent in the past four quarters.
The S&P 500 ended up 0.8 percent last week, closing a five-week run of gains, its first such winning streak this year.
"We're only couple of points away from an all-time high, and as we approach that, we're going to see a little bit of resistance," said Robert Pavlik, chief investment strategist at SlateStone Wealth LLC in New York.
With just 44 companies set to report this week and the calendar light on economic data, the spotlight will be on trade issues.
The S&P 500 e-minis were down 1.25 points, or 0.04 percent by 8:50 a.m. ET. The Dow e-minis were down 12 points, or 0.05 percent and the Nasdaq 100 e-minis were down 6 points, or 0.08 percent.
Berkshire Hathaway Inc rose 2.23 percent in premarket trading after the Warren Buffett-led conglomerate reported a 67 percent surge in quarterly operating profit.
Qualcomm and Advanced Micro Devices rose about 1.5 percent each following positive brokerage recommendations.
PepsiCo rose 0.8 percent after the company said Chief Executive Officer Indra Nooyi would step down in October.
Intel dropped 1.2 percent after Barclays downgraded the stock to "equal weight". (Reporting by Sruthi Shankar in Bengaluru; Editing by Anil D'Silva)