* Oil prices retreat; China factory activity slows
* Nike hit by downgrade, Under Armour by forecast cut
* Michael Kors jumps on strong sales growth
* Futures down: Dow 71 pts, S&P 7.8 pts, Nasdaq 13.8 pts (Adds details, comment, updates prices)
By Tanya Agrawal
June 1 (Reuters) - Wall Street looked set to begin the month in the red on Wednesday as falling oil prices and weak factory data from China worried investors as they try to anticipate the timing of the next U.S. rate hike.
China's official factory activity gauge expanded only marginally in May, data showed, while a private survey showed conditions deteriorated for a fifteenth straight month.
"This data are a barometer, to many, of economic activity and growth," said Andre Bakhos, managing director at Janlyn Capital in Bernardsville, New Jersey. "Any hiccup, any speed bump in China will thwart upside activity."
Oil prices fell on expectations of OPEC inaction on output as its focus stays firmly on market share, while concerns about China's economy weighed on the demand outlook.
"The market also keeps an eye on oil as another economic barometer. Weak oil, weak economy. Strong oil, stable economy," Bakhos said.
Dow e-minis were down 71 points, or 0.4 percent, at 8:51 a.m. ET (1251 GMT), with 27,314 contracts changing hands.
S&P 500 e-minis were down 7.75 points, or 0.37 percent, with 195,858 contracts traded.
Nasdaq 100 e-minis were down 13.75 points, or 0.3 percent, on volume of 28,167 contracts.
Data on Tuesday showed U.S. consumer confidence dipped, while a survey on business activity in U.S. Midwest also underwhelmed.
That does not bode well for the Institute of Supply Management's manufacturing survey for May, due at 10 a.m. ET, with traders saying that a weak reading could see chances of a rate hike in June recede.
The Federal Reserve releases its Beige Book, a compendium of anecdotes on the health of the economy at 2 p.m. The Fed caught investors off guard earlier this month when it signaled its next rate hike could be as soon as its June 14-15 meeting.
However, after the drop in oil prices and disappointing U.S. and China data, traders are pricing only a 22.5 percent chance of a hike in June, down from a probability of around 32 percent on Monday, according to the CME Group FedWatch tool.
Shares of Under Armour were down 3.6 percent at $36.37 premarket after the sports apparel and shoe maker cut its full-year forecast.
Bigger rival Nike fell nearly 3 percent to $53.60 after a Morgan Stanley downgrade on higher chances of a slowdown in U.S. sales due to competition and a weakening U.S. market.
Handbag maker Michael Kors rose 7 percent to $45.71 after posting its strongest sales growth in a year and announcing a new share buyback.
Demandware soared 56 percent to $74.88 after Salesforce.com agreed to buy the company in a $2.8 billion deal. Salesforce was down 2.1 percent at $82. (Reporting by Tanya Agrawal; Additional reporting by Mamidipudi Soumithri; Editing by Savio D'Souza)