US STOCKS-Wall St edges lower ahead of Fed, Facebook tumbles

* Energy up alongside rise in crude oil

* Facebook (NasdaqGS: FB - news) down as expenses seen rising

* Orbital Sciences (NYSE: ORB - news) halted after rocket explosion

* Dow up 0.1 pct, S&P flat, Nasdaq down 0.4 pct (Updates to afternoon trading)

By Ryan Vlastelica

NEW YORK, Oct 29 (Reuters) - U.S. stocks fell in a broad decline on Wednesday, with material shares leading the market lower as investors looked ahead to a statement from the U.S. Federal Reserve as it winds down its economic stimulus program.

Strength in energy shares helped to offset some of the weakness in materials, though the tech-heavy Nasdaq was pressured by a slump in Facebook as investors fretted over its spending plans.

DuPont lost 1.4 percent to $67.03 and was the largest drag on the S&P materials sector after it said there were "competitive advantages" in keeping its businesses together. Activist investor Nelson Peltz has urged DuPont to separate its various businesses in a move that has supported the company's shares.

Equities mostly held on to recent gains, with the S&P 500 up 6.3 percent in the last nine sessions as earnings have mostly been strong. So far this reporting season, 75.3 percent of S&P 500 companies have exceeded profit expectations, according to Thomson Reuters data, above the long-term average of 63 percent.

"The trend today is company-specific," said Kim Forrest, senior equity research analyst at Fort Pitt Capital Group in Pittsburgh.

She said the takeaway from a glut of company calls is "the U.S. is the best house in an ugly neighborhood and that doesn't seem to be abating."

Energy shares climbed 0.6 percent as the top-performing sector of the day by far, tracking a 1.4 percent increase in crude oil, which was boosted as U.S. crude stockpiles rose by less than expected last week.

At 1:06 p.m. EDT (1706 GMT) the Dow Jones industrial average fell 19.05 points, or 0.11 percent, to 16,986.7, the S&P 500 lost 3.48 points, or 0.18 percent, to 1,981.57 and the Nasdaq Composite dropped 24.54 points, or 0.54 percent, to 4,539.76.

The Fed is seen likely to announce that it will no longer add to its holdings of Treasury bonds and mortgage-backed securities after it ends a two-day policy meeting later on Wednesday, effectively ending a program that at its peak pumped $85 billion a month into the financial system.

Facebook Inc fell 6.1 percent to $75.84 the day after the social network announced an increase in spending in 2015 and projected a slowdown in revenue growth this quarter.

Shares (Berlin: DI6.BE - news) of both Orbital Sciences Corp and Alliant Techsystems were halted in afternoon trading, with Orbital last trading down 15.7 percent to $25.60 and Alliant last down 5.2 percent to $123.

The halt and decline came a day after Orbital's unmanned rocket exploded seconds after liftoff from a commercial launch pad in Virginia, marking the first accident since NASA turned to private operators to deliver cargo to the International Space Station. Orbital is in the midst of merging with Alliant's aerospace and defense division. (Additional reporting by Rodrigo Campos; Editing by Chris Reese)