* U.S. services sector grows in April at fastest pace in 8 months
* JPMorgan leads banks lower after trading revenue warning
* Pfizer's revenue below expectations, shares fall
* Indexes down: Dow 0.5 pct, S&P 0.3 pct, Nasdaq 0.2 pct (Updates prices, adds comment)
By Rodrigo Campos
NEW YORK, May 5 (Reuters) - U.S. stocks fell on Monday on concern China's economy is continuing to lose momentum and the confrontation between Ukraine and pro-Russia separatists escalated.
Bank shares led the market lower with JPMorgan Chase down 2.3 percent to $54.33. The bank said late on Friday it expects second-quarter revenue from bond and equity trading to decline by about 20 percent from a year earlier.
Geopolitical events kept the market under pressure as Ukrainian forces were ambushed by separatists on Monday, triggering heavy fighting on the outskirts of the rebel stronghold of Slaviansk, a day after a Ukrainian police station in Odessa was stormed.
On the macro front, growth in the U.S. services sector in April rose at the fastest pace in eight months. The data slightly offset news that China's manufacturing sector contracted for a fourth consecutive month in April, adding to concerns over the health of the world's second-largest economy.
"Ukraine and China were likely contributors to the low open," said Peter Jankovskis, co-chief investment officer at OakBrook Investments in Lisle, Illinois.
He said the better-than expected U.S. data "explains why we're off the early lows" and Ukraine's pull on equities could soften as the session advances.
"We could see more gains later on, after European markets close," Jankovskis said.
The Dow Jones industrial average fell 77.16 points or 0.47 percent, to 16,435.73, the S&P 500 lost 5.55 points or 0.3 percent, to 1,875.59 and the Nasdaq Composite dropped 7.536 points or 0.18 percent, to 4,116.362.
Pfizer Inc added to the gloomy sentiment as the biggest U.S. drugmaker reported revenues well below analysts' expectations. Shares fell 2.6 percent to $29.95.
Target Corp shares fell 3 percent to $60.15 after news that Chief Executive and Chairman Gregg Steinhafel will leave the company in the wake of a data breach late last year that hurt profits, shook customer confidence in the No. 3 U.S. retailer and prompted congressional hearings.
German aircraft seating maker Recaro said it was studying the possibility of buying assets from B/E Aerospace after the U.S. company announced a surprise review. B/E Aerospace shares jumped 10.9 percent to $98.69.
Occidental Petroleum, the fourth-largest U.S. oil and gas company, reported a better-than-expected profit for the third straight quarter, helped by higher prices for crude oil and natural gas in the United States. Shares rose 0.6 percent to $95.01. (Editing by Bernadette Baum and Nick Zieminski)