* Tyco jumps after deal to merge with Johnson Controls
* Caterpillar falls after Goldman slaps with "sell" rating
* Twitter down, 4 top executives to leave co
* Indexes down: Dow 0.47 pct, S&P 0.69 pct, Nasdaq 0.63 pct (Updates to late afternoon)
By Lewis Krauskopf
Jan 25 (Reuters) - Wall Street stumbled on Monday after its first positive week of 2016, pulled lower by further weakness in oil prices as energy shares led declines.
Oil prices fell more than 5 percent on concerns of oversupply after news that Iraq's output reached a record last month.
The S&P energy group dropped 3.2 percent, the worst performing sector. Exxon and Chevron were each off nearly 2 percent, while ConocoPhillips tumbled 7 percent after Barclays said the company should cut its dividend by at least 75 percent.
Wall Street is coming off its first week of gains in the year, with the three major indexes posting solid increases on Friday.
During the poor start for the year for U.S. stocks, their performance has been closely correlated with the price of oil, although some investors said Wall Street's more modest decline on Monday meant the two assets could be decoupling somewhat.
"It looks like investors are trying to grapple with what happened last week and if we've seen the bottom here, at least in the short run," said Chuck Carlson, chief executive officer at Horizon Investment Services in Hammond, Indiana.
At 2:31 p.m. ET, the Dow Jones industrial average was down 76.05 points, or 0.47 percent, to 16,017.46, the S&P 500 lost 13.23 points, or 0.69 percent, to 1,893.67 and the Nasdaq Composite dropped 28.78 points, or 0.63 percent, to 4,562.40.
Nine of the 10 major S&P sectors were lower, with the materials group off 2.4 percent.
Investors will look to data about the economy's direction later this week as many heavyweight companies report quarterly results. Federal Reserve policymakers meet on Tuesday and Wednesday for the first time since raising interest rates in December.
McDonald's was up 1.4 percent at $120.10. The Dow component reported better-than-expected same-store sales.
D.R. Horton shares fell 4.3 percent to $26.51 as the No. 1 U.S. homebuilder reported lower-than-expected revenue as its home sales fell in all regions but the Southeast.
Tyco International jumped 11.1 percent to $33.98 after Johnson Controls said it would merge with the Ireland-based fire protection and security systems maker. Johnson Controls was down 2.5 percent at $34.71.
Shares of Caterpillar were down 4.6 percent at $58.16 after Goldman Sachs cut its rating on the stock to "sell".
Twitter was down 3.6 percent at $17.19 after Chief Executive Jack Dorsey said four senior executives would leave the social media company.
Declining issues outnumbered advancing ones on the NYSE by 2,398 to 633, for a 3.79-to-1 ratio on the downside; on the Nasdaq, 1,891 issues fell and 886 advanced for a 2.13-to-1 ratio favoring decliners.
The S&P 500 posted 3 new 52-week highs and 15 new lows; the Nasdaq recorded 11 new highs and 79 new lows. (Reporting by Lewis Krauskopf in New York, additional reporting by Abhiram Nandakumar in Bengaluru; Editing by Anil D'Silva and Nick Zieminski) ))