US stocks dip as presidential polls tighten

Wall Street stocks edged lower Monday as rising uncertainty over the US presidential campaign countered the lift from major acquisitions by General Electric and CenturyLink.

Markets are recalibrating the US presidential contest after the shock FBI announcement that it was reviewing a newly discovered trove of emails linked to Hillary Clinton's controversial private server, which sent shares tumbling Friday.

Clinton has been seen by Wall Street as the safer choice for the White House compared with Donald Trump, who is viewed as unpredictable.

At the closing bell, the Dow Jones Industrial Average stood at 18,142.42, down 0.1 percent.

Both the S&P 500 and Nasdaq lost 0.01 percent. The broad-based S&P finished at 2,126.15, while the tech-rich Nasdaq Composite was at 5,189.13.

Baker Hughes sank 6.3 percent after it agreed to merge with GE's oilfield business, with GE garnering control of the venture in exchange for $7.4 billion in dividend payments. GE fell 0.4 percent.

Level 3 Communications jumped 3.9 percent on news it will be bought by CenturyLink for $34 billion. CenturyLink, the third largest US telecommunications carrier, tumbled 12.5 percent.