US STOCKS-Futures point to higher open on M&A activity
* M&A deal lifts sentiment; UnitedHealth unit to buy Catamaran
* Oil prices volatile amid potential deal with Iran
* Strength in dollar could be a concern
* Futures up: Dow 121 pts, S&P 10.5 pts, Nasdaq 27.75 pts (Updates prices, adds Teva deal and economic data)
By Ryan Vlastelica
NEW YORK, March 30 (Reuters) - U.S. stock index futures indicated a higher open on Monday, pointing to a second straight daily gain as four M&A deals in the biotech sector lifted market sentiment after a recent bout of weakness.
Despite that, energy shares could come under pressure as crude oil fell on a possible deal with Iran, which could bring an end to sanctions and allow an increase in the country's oil exports. Crude oil fell 0.5 percent to $48.68 per barrel after falling as 2.5 percent earlier in the session.
Separately, an increase in the U.S. dollar could weigh on multi-nationals. The U.S. dollar index rose 0.7 percent.
Both the dollar and commodity prices have given investors reason to be cautious of late, especially going into the first-quarter earnings season, where traders will look to see how much oil prices and the strong U.S. dollar will impact corporate bottom lines. Last week, the S&P 500 fell 2.2 percent, the Dow lost 2.3 percent and the Nasdaq declined 2.7 percent. Continuación...