US STOCKS-Wall St flat as ISM data offsets Ukraine concern
* Services sector grows in April, fastest pace in 8 months
* JPMorgan leads banks lower after trading revenue warning
* Pfizer's revenue below expectations, shares fall
* Indexes: Dow flat, S&P up 0.07 pct, Nasdaq up 0.11 pct (Updates to midday, changes byline)
By Chuck Mikolajczak
NEW YORK, May 5 (Reuters) - U.S. stocks were little changed on Monday, as upbeat economic data was offset by concerns over an escalation of tensions between Ukraine and pro-Russia separatists.
Equities initially 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.
But equities rebounded after the Institute for Supply Management said its services sector index rose to 55.2 in April, the fastest pace in eight months, from 53.1 in March, topping expectations for a read of 54.1.
"It's more confirmation the economy is strengthening and we are headed for stronger growth," said Peter Cardillo, chief market economist at Rockwell Global Capital in New York. Continuación...