* Fed's John Williams sees 2-3 rate hikes in 2016
* Yellen to speak later in the week
* Monsanto jumps after Bayer's $62 bln buyout offer
* Indexes: Dow down 0.1 pct, S&P down 0.09 pct, Nasdaq up 0.17 pct (Updates to open)
By Tanya Agrawal
May 23 (Reuters) - Wall Street opened little changed on Monday as investors awaited speeches by U.S. Federal Reserve officials this week for clues on the timing of the next interest rate increase.
The Fed surprised investors when the central bank's minutes released last week opened the door to a rate hike in June, roiling financial markets.
San Francisco Fed President John Williams said on Monday that two-to-three rate hikes this year were reasonable and that inflation was on track to meet the Fed's goal of 2 percent in the next year or two.
St. Louis Federal Reserve President James Bullard also said a relatively tight labor market in the United States may put upward pressure on inflation, raising the case for higher interest rates.
The probability for a June rate hike rose to 30 percent on Friday from about 4 percent at the start of the week, according to CME Group's FedWatch site.
"Focus remains on the Fed's next move and as you take a look at all the economic indicators we got last week, it certainly suggests that the economy is improving," said Peter Cardillo, chief market economist at First Standard Financial in New York.
"This is going to keep the market in a tight trading range."
At 9:37 a.m. ET (1337 GMT) the Dow Jones industrial average was down 16.84 points, or 0.1 percent, at 17,484.1, the S&P 500 was down 1.75 points, or 0.09 percent, at 2,050.57 and the Nasdaq Composite was up 8.23 points, or 0.17 percent, at 4,777.79.
Apple's 1.3 percent rise provided the biggest boost to the Nasdaq.
Six of the 10 major S&P sectors were higher, with the material index's 0.83 percent rise leading the gainers.
Monsanto rose 6.8 percent to $108.11 after German drugs and crop chemicals group Bayer offered to buy the U.S. seeds company for $62 billion in cash.
Philadelphia Fed chief Patrick Harker speaks on the economic outlook in Philadelphia at 6:30 p.m. ET.
This week will see Fed speakers, including Fed Chair Janet Yellen, present their views on the economy that could provide more clarity on the pace of rate hikes.
The S&P 500 eked out gains last week after three straight weeks of losses, while the Nasdaq snapped a four-week losing streak on Friday. Despite gains, the Dow ended its fourth consecutive week in the red.
Brent oil prices fell for a fourth consecutive session on Monday after Iran insisted it would not freeze crude output, returning investor attention to a global glut.
Tribune Publishing fell 12.7 percent to $12.42 after it rejected Gannett's latest takeover offer.
American Capital was up 2.4 percent at $16 after investment company Ares Capital said it would buy the company in a deal valued at $3.4 billion. Ares was down 1.6 percent at $14.95.
Declining issues outnumbered advancing ones on the NYSE by 1,342 to 1,240. On the Nasdaq, 1,243 issues rose and 957 fell.
The S&P 500 index showed four new 52-week highs and no new lows, while the Nasdaq recorded 16 new highs and five new lows. (Reporting by Tanya Agrawal; Editing by Anil D'Silva)