* Fed's Williams says sees 2-3 rate hikes in 2016
* Yellen to speak later in the week
* Monsanto jumps after Bayer's $62 bln buyout offer
* Futures: Dow down 12 pts, S&P down 1.5 pts, Nasdaq up 2.5 pts (Adds details, comment, updates prices)
By Tanya Agrawal
May 23 (Reuters) - Wall Street looked set to open little changed on Monday as investors awaited speeches by U.S. Federal Reserve officials this week for clues on the timing of the next rate increase.
The Fed surprised investors when the central bank's minutes released last week opened the door to a rate increase 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."
S&P 500 e-minis were down 1.5 points, or 0.07 percent, with 196,543 contracts traded at 8:25 a.m. ET (1225 GMT). Nasdaq 100 e-minis were up 2.5 points, or 0.06 percent, on volume of 26,763 contracts. Dow e-minis were down 12 points, or 0.07 percent, with 30,613 contracts changing hands.
Philadelphia Fed chief Patrick Harker speaks on the economic outlook in Philadelphia at 6:30 p.m. ET.
This week will see a host of 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.
Monsanto rose 8.1 percent to $109.85 in premarket trading after German drugs and crop chemicals group Bayer offered to buy U.S. seeds company for $62 billion in cash.
Tribune Publishing fell 8.2 percent to $13.06 after it rejected Gannett's latest takeover offer.
American Capital was up 7.2 percent at $16.75 after investment company Ares Capital said it would buy the company in a deal valued at $3.4 billion. (Reporting by Tanya Agrawal; Editing by Anil D'Silva)