US STOCKS-Wall St weighed down by energy, materials stocks
* Crude oil falls after last week's gains
* Tyco jumps after deal to merge with Johnson Controls
* Twitter falls as 4 top executives to leave co
* Indexes down: Dow 0.39 pct, S&P 0.59 pct, Nasdaq 0.46 pct (Updates to early afternoon)
By Abhiram Nandakumar
Jan 25 (Reuters) - Wall Street looked set to snap a two-day rally in muted trade on Monday as retreating oil prices pulled down materials and energy stocks.
Crude prices resumed their slide after a strong two-day run last week, falling more than 4 percent on news that Iraq flooded a heavily oversupplied oil market with record output.
Wall Street is coming off its first week of gains in the year, with the three major indexes rising 2 percent on Friday.
Investors, already rattled by the volatile start to the year and a steep fall in oil prices, are awaiting U.S. GDP data on Friday for a reading on the health of the economy and the U.S. Federal Reserve's policy meeting on Jan. 26-27. Continuación...