* Futures down: Dow 61 pts, S&P 6.75 pts, Nasdaq 11.75 pts
By Tanya Agrawal
June 1 (Reuters) - U.S. stock index futures started the month on a dour note on Wednesday as falling oil prices and weak factory data from China worried investors.
* 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.
* 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.
* 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 (1400 GMT), 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 central bank 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.
* The S&P 500 wrapped up its third straight month of gains on a flat note on Tuesday as weaker energy shares countered a rise in safe-haven utilities.
* Shares of Under Armour were down 4.5 percent at $36.02 premarket after the sports apparel and shoe maker cut its full-year forecast.
* Bigger rival Nike fell 3.5 percent to $53.30 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 jumped 12.1 percent to $47.90 after posting its strongest sales growth in a year and announcing a $1 billion share buyback.
* Demandware soared 52.12 percent to $73 after Salesforce.com agreed to buy the company in a $2.8 billion deal. Salesforce was down 1.3 percent at $82.60.
Futures snapshot at 7:05 a.m. ET:
* Dow e-minis were down 61 points, or 0.34 percent, with 23,233 contracts changing hands.
* S&P 500 e-minis were down 6.75 points, or 0.32 percent, with 154,831 contracts traded.
* Nasdaq 100 e-minis were down 11.75 points, or 0.26 percent, on volume of 23,014 contracts. (Reporting by Tanya Agrawal; Editing by Savio D'Souza)