* Factory orders increase in July
* Airline shares fall with Delta
* Investors wait for ECB policy meeting
* Dow up 0.06 pct, S&P down 0.08 pct, Nasdaq off 0.56 pct (Updates to close)
By Akane Otani
NEW YORK, Sept 3 (Reuters) - U.S. stocks ended mostly down on Wednesday, as a decline in Apple shares dragged the Nasdaq lower and investors held off on big bets before the European Central Bank's upcoming policy meeting.
Apple shares slid 4.2 percent to $98.94 in their worst percentage decline since Jan. 28. At least one brokerage mulled downgrading the stock as Apple grappled with a possible security breach of its iCloud service a week before the launch of its new iPhone.
Rival Samsung Electronics Co Ltd, meanwhile, launched a virtual reality headset for its new Galaxy Note 4 phablet using technology from Oculus VR, a company that Facebook Inc acquired for $2 billion.
Apple's decline weighed on the technology sector, which lost 0.7 percent and was the worst performing of the 10 major S&P groups. It also weighed down the benchmark S&P index, which had hit a record intraday high of 2,009.28 earlier in the day but finished nearly unchanged.
"The market has been on pause today. Everything on the economic front has been better than expected, but there's a bit of trepidation about the upcoming ECB meeting," said Douglas Cote, chief market strategist at Voya Investment Management in New York.
The European Central Bank will hold a monthly policy meeting on Thursday, where investors will look for clues that the ECB may launch a bond-buying program.
The Dow Jones industrial average rose 10.72 points, or 0.06 percent, to 17,078.28. The S&P 500 ended down 1.55 points, or 0.08 percent, at 2,000.73. The Nasdaq Composite lost 25.62 points, or 0.56 percent, to end at 4,572.57.
Stocks had gained earlier after officials from Ukraine and Russia said they were close to an agreement to stop fighting in eastern Ukraine, but confusion lingered as Russia announced plans to carry out military exercises.
Airline shares fell after Delta Airlines, down 5.2 percent to $38.82, trimmed its operating margin forecast and said its international passenger traffic fell slightly in August. Shares (Frankfurt: DI6.F - news) of American Airlines Group Inc fell 3.4 percent to $39.14.
The latest data pointed to continued recovery in the economy. New orders for manufactured goods increased a record 10.5 percent in July, and August auto sales were unexpectedly strong, due in part to heavy discounting.
Housing stocks were weak, weighed down by a 4.7 percent decline in Toll Brothers (NYSE: TOL - news) to $33.95 after the largest U.S. luxury homebuilder posted quarterly results. The PHLX housing index lost 1.6 percent. (Editing by Bernadette Baum, Nick Zieminski and Chizu Nomiyama)