* Brent crude set for best 4-day run in a month
* Chevron up 2 pct, Exxon rises 1.5 pct
* Yum Brands slumps 18 pct on China worries
* McDonald's falls after Yum's report
* Indexes up: Dow 0.79 pct, S&P 0.69 pct, Nasdaq 0.49 pct (Updates to open)
By Abhiram Nandakumar
Oct 7 (Reuters) - Wall Street opened higher on Wednesday as crude oil prices rose for the fourth day in a row, with Brent crude on track to post its best 4-day run in more than a month.
Chevron rose 2.3 percent and Exxon rose 1.6 percent, providing the biggest boosts to the S&P 500.
The S&P energy index gained 1.9 percent, leading the advancers among the 10 major S&P sectors. Nine of the 10 sectors were up.
Brent crude and U.S. light crude were up about 2 percent after data showed a fall in U.S. inventories after two years of surplus.
Global stocks were also boosted on Wednesday by mining and energy shares as investors bought into the prospect of continued support from the world's central banks.
Expectations that the Federal Reserve will lift interest rates this year are fading, with concerns mounting about slowing global growth and its effect on corporate results.
Investors will focus on quarterly earnings reports over the next few weeks, said Peter Cardillo, chief market economist at Rockwell Global Capital in New York.
PepsiCo's better-than-expected quarterly results on Tuesday suggested companies may not fare as badly as expected, he said.
S&P 500 companies are expected to report a 4.2 percent fall in third-quarter profit, the biggest decline in six years, according to Thomson Reuters data.
At 9:40 a.m. ET, the Dow Jones industrial average was up 133.02 points, or 0.79 percent, at 16,923.21. The S&P 500 was up 13.68 points, or 0.69 percent, at 1,993.6 and the Nasdaq composite index was up 23.04 points, or 0.49 percent, at 4,771.40.
U.S. stocks closed lower on Tuesday, snapping a five-day winning streak, led by a rout in healthcare and biotech stocks. The S&P health care sector was up 0.65 percent in early trading on Wednesday.
Yum Brands slumped almost 18 percent to $68.50 after it cut its full-year profit forecast due to a slower-than-expected recovery in China and a strong dollar.
Dow component McDonald fell 1 percent to $100.78 and was the biggest drag on the Dow. NU Skin, a skin care and nutritional products maker, sank 16.3 percent to $39.01. Both companies have a large exposure to China.
Adobe fell 3.9 percent to $81.89 after lowering its 2016 profit forecast.
Twitter rose 2.4 percent to $28.27 after Saudi Arabian billionaire Prince Alwaleed bin Talal and his investment firm raised their stake to more than 5 percent.
Advancing issues outnumbered decliners on the NYSE by 2,245 to 459. On the Nasdaq, 1,514 issues rose and 770 fell.
The S&P 500 index showed four new 52-week highs and no new lows, while the Nasdaq recorded 19 new highs and seven new lows. (Reporting by Abhiram Nandakumar in Bengaluru; Editing by Savio D'Souza)