* Yellen appears before Congressional committee at 10:00 a.m. ET
* Tempur Sealy drops on disappointing forecast
* Futures up: Dow 12 pts, S&P 0.5 pts, Nasdaq 4 pts (Adds details, comments, updates prices)
By Yashaswini Swamynathan
Sept 28 (Reuters) - Wall Street was set to open little changed on Wednesday as investors awaited Federal Reserve Chair Janet Yellen's testimony before a Congressional committee.
Yellen's testimony will be watched for clues on the timing of the next interest rate hike, a week after the central bank held rates steady but suggested that a move could come later this year.
Five Fed officials from various states are also scheduled to speak at separate events, including voting members Esther George, James Bullard and Loretta Mester.
Stocks, which have rallied in the absence of an interest rate hike this year, are highly sensitive to Fed comments due to a lack of consensus on the timing of future increases.
"I don't expect a major shift in Fed rhetoric, which is to make hawkish comments, but follow with dovish action," said Adam Sarhan, chief executive at Sarhan Capital.
"Unless Yellen or one of the other Fed heads go way off reservation and make a statement, I don't expect massive fireworks today."
Economists say the Fed may pull the trigger on rates in December as the November meeting comes days ahead of the U.S. presidential election.
Dow e-minis were up 12 points, or 0.07 percent at 8:21 a.m. ET, with 24,740 contracts changing hands.
S&P 500 e-minis were up 0.5 points, or 0.02 percent, with 178,301 contracts traded.
Nasdaq 100 e-minis were up 4 points, or 0.08 percent, on volume of 28,074 contracts.
Wall Street closed higher on Tuesday, helped by consumer and technology companies and as Hillary Clinton was seen to be the winner of the first presidential debate.
Analysts say Clinton's neck-to-neck race to the White House with Donald Trump is likely to spark volatility in the markets in the weeks ahead.
Mattress maker Tempur Sealy's shares plunged 21.8 percent in premarket trading after the company forecast disappointing full-year sales.
Nike dropped 2.6 percent to $53.85 after the shoemaker's future orders missed analysts' estimates for the third time in a row, attracting a slew of price targets by brokerages.
Wells Fargo rose 0.93 percent in heavy premarket trading, following its statement that CEO John Stumpf would forfeit unvested equity awards worth about $41 million and will not get a salary while the board investigates its sales practices. (Reporting by Yashaswini Swamynathan in Bengaluru; Editing by Anil D'Silva)