* Alphabet, Amazon, Netflix at record highs
* Private sector adds most jobs since June
* Yellen to speak at 12:25 p.m. ET
* November jobs report expected on Friday
* Dow down 0.21 pct, S&P down 0.3 pct, Nasdaq up 0.14 pct (Adds quote, updates prices)
By Sweta Singh
Dec 2 (Reuters) - The S&P 500 and the Dow drifted lower on Wednesday as investors looked for clues from Federal Reserve Chair Janet Yellen on the timing of an interest rate increase, but record highs at Alphabet, Amazon and Netflix lifted Nasdaq.
Yellen will speak before the Economic Club of Washington at 12:25 p.m. ET (1625 GMT). She also testifies on the economic outlook before a joint committee of Congress on Thursday.
Data showed U.S. private employers added the most number of jobs since June.
"The preponderance of data seems to support the removal of the emergency monetary policy at the next meeting," said Bill Northey, chief investment officer of the private client group at U.S. Bank.
The Fed is scheduled to meet on Dec. 16, when it is expected to raise interest rates for the first time in nearly a decade.
Economic data has not been playing ball with the Fed's policy plans in recent weeks and has been mixed at best. While construction spending has risen, there has been a sharp downturn in the manufacturing surveys along with weaker retail sales.
However, job growth has been strong and Friday's employment report is expected to show that the U.S. economy added 200,000 jobs in November.
Adam Sarhan, chief executive of Sarhan Capital in New York, expects some sideways trading ahead of Yellen's speech.
"Investors are waiting for more cards to come out of the deck and with the ECB meeting tomorrow and the Friday jobs number, there are a lot more data points to digest," he said.
The European Central Bank is expected to ramp up its trillion-euro bond-buying program on Thursday.
Shares of Amazon touched a record high of $684.82, while those of Netflix rose as much as 4.8 percent to $131.35. Alphabet rose as much as 1.2 percent to $793.04.
At 11:29 a.m. EDT the Dow Jones industrial average was down 37.01 points, or 0.21 percent, at 17,851.34, the S&P 500 was down 6.31 points, or 0.3 percent, at 2,096.32 and the Nasdaq Composite was up 7.01 points, or 0.14 percent, at 5,163.31.
Nine of the 10 major S&P 500 sectors were lower with the energy index's 1.83 percent fall leading the decliners.
The CME Group's analysis of 30-day Fed funds futures prices shows investors place the probability of an interest rate hike this month at 75 percent.
A host of Fed speakers make appearances through the day, including San Francisco Fed President John Williams, Federal Reserve Board Governor Daniel Tarullo and Philadelphia Fed President Patrick Harker.
Atlanta Fed President Dennis Lockhart said there is a compelling" case for an initial hike in interest rates during the Fed's next meeting.
Yahoo shares were up 6.9 percent at $36.02 on Wednesday after reports that the company was weighing a sale of its core Internet business. Alibaba, in which Yahoo has a stake, was up 1.1 percent at $84.95.
Zafgen was down 57.9 percent at $6.66 after a second patient died during its obesity drug trial.
Declining issues outnumbered advancing ones on the NYSE by 1,956 to 929. On the Nasdaq, 1,319 issues fell and 1,286 advanced.
The S&P 500 index showed 19 new 52-week highs and 7 new lows, while the Nasdaq recorded 68 new highs and 32 new lows. (Reporting by Sweta Singh; Editing by Don Sebastian)