US STOCKS-Wall St ends May with whimper as energy shares slump
* S&P 500 still tallies gains for 3rd straight month
* April consumer spending up; May consumer confidence slips
* Energy sector lags as oil turns lower
* Celator jumps over 70 pct after agreeing to be acquired
* Dow down 0.48 pct, S&P down 0.1 pct, Nasdaq up 0.29 pct (Updates with close of U.S. market)
By Lewis Krauskopf
May 31 (Reuters) - The S&P 500 wrapped up its third straight month of gains on a flat note on Tuesday as weaker energy shares countered a rise in safe-haven utilities.
The Nasdaq closed higher on Tuesday, and ended up 3.6 percent for the month, the best performance of the three major indexes. The Dow eked out gains for May to notch its fourth straight positive month.
Data on Tuesday showed U.S. consumer spending recorded its biggest increase in more than six years in April as households stepped up purchases of automobiles, while another report showed an ebb in consumer confidence in May. Continuación...