* Indexes advance for October
* Exxon Mobil shares rise after results beat Wall St forecast
* Chicago PMI well above expectations
* Jobless claims fall slightly less than expected
* Dow down 0.5 pct, S&P 500 off 0.4 pct, Nasdaq down 0.3 pct
By Caroline Valetkevitch
NEW YORK, Oct 31 (Reuters) - U.S. stocks finished lower on Thursday as the Federal Reserve's statement the day before added to investors' anxiety about the timing of a pullback in its stimulus program.
While it was a second consecutive day of losses for the market, all three major indexes ended October with solid gains.
Dragging on the Dow and the S&P 500, Visa Inc lost 3.5 percent to $196.67 after the world's largest credit and debit card company reported a 28 percent drop in quarterly profit.
The U.S. central bank on Wednesday said it will keep buying $85 billion of bonds per month, citing weaker economic signals, but it removed a phrase from a previous statement expressing worries about credit conditions, which some investors interpreted as a sign that the Fed could begin tapering earlier than expected.
"That leaves tapering on the table for December," said Michael O'Rourke, chief market strategist at JonesTrading, in Greenwich, Connecticut.
Before the Fed's meeting, many market participants were anticipating that the stimulus plan would not change until at least early next year.
The Fed's accommodative monetary policy in recent years has contributed to the stock market's rally.
The Dow Jones industrial average fell 73.01 points, or 0.47 percent, to close at 15,545.75. The S&P 500 lost 6.77 points, or 0.38 percent, to finish at 1,756.54. The Nasdaq Composite dropped 10.91 points or 0.28 percent, to end at 3,919.71.
The S&P 500 closed near its intraday low, with a wave of end-of-session selling marked by sell-order imbalances near the close.
"This was more of an order flow thing," said Dennis Dick, proprietary trader at Bright Trading LLC in Las Vegas. "Some participants, some institutions wanted out big time, and they got out."
For the month, the Dow gained 2.8 percent, the S&P 500 added 4.5 percent and the Nasdaq rose 3.9 percent.
The S&P 500 is up 23.2 percent for the year so far.
"It's already at nosebleed heights and it could go higher, but people are focusing on the rewards and not the risks," including ongoing weakness in the economy," said Uri Landesman, president of Platinum Partners in New York.
Among the day's gainers, shares of Exxon Mobil Corp , the world's largest publicly traded oil company, helped support the Dow and the S&P 500, rising 0.9 percent to $89.62 after the company reported adjusted third-quarter earnings that beat expectations.
Expedia jumped 18 percent to $58.97 and ranked as the S&P 500's best percentage gainer, a day after reporting third-quarter earnings that exceeded expectations.
Facebook reported strong growth in its mobile advertising business late on Wednesday, though it said it didn't plan to boost the frequency of ads shown to users. Facebook's stock rose 2.4 percent to close at $50.21.
With results in from 355 companies in the S&P 500, 68.2 percent have topped Wall Street's expectations, above both the 63 percent beat rate since 1994 and the 66 percent beat rate for the past four quarters, according to Thomson Reuters data.
Revenue performance has been weaker, however, with 53.6 percent of companies exceeding expectations, shy of the 61 percent beat rate since 2002, but above the 49 percent rate for the past four quarters.
Thursday's economic data was mixed. A gauge of business activity in the Midwest surged past expectations in October, while weekly initial jobless claims dipped in the latest week.