By Caroline Valetkevitch
NEW YORK (Reuters) - U.S. stocks were up slightly on Monday as concerns over an escalation of tensions between Ukraine and pro-Russia separatists were offset by data showing strength in the services sector.
The Institute for Supply Management said its services sector index rose in April, hitting the fastest pace in eight months and topping expectations.
Shares had opened lower, weighed by geopolitical events 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.
"We shook off a lot of the morning jitters, and the ISM services came out and showed pretty good growth, and that obviously brought back some buyers," said Ryan Detrick, senior technical strategist at Schaeffer's Investment Research in Cincinnati, Ohio.
Still, bank shares were under pressure as JPMorgan Chase
The Dow Jones industrial average <.DJI> rose 25.4 points or 0.15 percent, to 16,538.29, the S&P 500 <.SPX> gained 3.6 points or 0.19 percent, to 1,884.74 and the Nasdaq Composite <.IXIC> added 12.957 points or 0.31 percent, to 4,136.854.
Energy shares were among the best performers, with the S&P energy index <.SPNY> up 0.5 percent.
Occidental Petroleum
Pfizer Inc
Target Corp
German aircraft seating maker Recaro said it was studying the possibility of buying assets from B/E Aerospace
(Additional reporting by Chuck Mikolajczak; Editing by Bernadette Baum and Nick Zieminski)