US STOCKS-Wall St dips after rally; indexes set for quarterly gain
* Oil prices weaken for third straight day
* Charter to buy Bright House for about $10 bln
* Nasdaq set for longest-ever streak of quarterly gains
* Dow down 0.4 pct, S&P 500 and Nasdaq both fall 0.3 pct (Adds economic data)
By Ryan Vlastelica
NEW YORK, March 31 (Reuters) - U.S. stocks fell on Tuesday in a modest retreat from the previous session's sharp rally, but major indexes remained on track for a positive first quarter and the S&P 500 was set for its ninth straight quarterly rise.
Energy shares were in focus as crude oil fell 1.4 percent to $48 per barrel, sending the S&P Energy index down 0.6 percent as one of the weakest industry groups of the day. Exxon Mobil Corp fell 0.7 percent to $85.06.
Oil was pressured as Iran and six world powers entered a final day of talks on a nuclear deal that could see the energy-rich country increase oil exports. The talks come when oversupply is already a major concern for energy investors, having contributed to crude falling more than 50 percent from a high in June.
Endurance Specialty Holdings Ltd agreed to buy reinsurer Montpelier Re Holdings Ltd for about $1.83 billion, while Charter Communications Inc agreed to acquire Bright House Networks in a roughly $10 billion deal. Continuación...