US STOCKS-Wall St slips in volatile session on quarter's last day
* S&P 500 on track to end June lower, but positive for quarter
* Accenture and BlackBerry both tumble after results
* Molycorp climbs after SEC investigation ends
* Dow down 0.4 pct, S&P 500 off 0.1 pct, Nasdaq up 0.1 pct
By Ryan Vlastelica
NEW YORK, June 28 (Reuters) - U.S. stocks edged mostly lower in a volatile session on Friday, with investors finding little reason to push shares higher after a three-day rally.
Shares fluctuated between steep losses and modest gains, trading flat for much of the session before pulling back. Technology shares were among the weakest of the day, pressured by weak corporate results, but the losses were partially offset by strength in energy and material shares.
Cyclical groups, which include materials and are tied to the pace of economic growth, have rallied this week on receding concerns that the Federal Reserve's stimulus program - widely credited with fueling the market's gains this year - would end soon.
Last week, Fed Chairman Ben Bernanke suggested the policy could be slowed if the economy improves, resulting in a selloff of nearly 5 percent, though that subsequently dissolved on signs that the end of the stimulus program wasn't imminent. Continued...