US STOCKS-Wall St cuts losses late to end tad lower
* Tumbling oil weighs on energy stocks; materials rise
* Volatile trading session with heavy volume
* Yellen to defend Fed rate hikes in Congress
* Indexes down: Dow 0.1 pct, S&P 0.1 pct, Nasdaq 0.4 pct (Adds details on Internet names, paragraphs 13-14)
By Caroline Valetkevitch
Feb 9 (Reuters) - U.S. stocks ended a volatile session slightly lower on Tuesday as a late-day rally led by materials and healthcare shares offset another big drop in oil prices.
Energy was the day's weakest sector, with the energy index falling 2.5 percent as U.S. crude settled 5.9 percent lower.
Shares of Anadarko Petroleum dropped 7 percent to $37.24. The company announced late in the session that it was cutting its dividend, preserving cash at a time when sliding oil prices have fueled losses.
Pfizer, up 1.9 percent, and Gilead, up 2.3 percent, gave the biggest boosts to the S&P 500, while the S&P health care index rose 0.7 percent, the second-best performing sector of the day after materials, up 1.2 percent. Continuación...