Wall Street eased lower in early dealings as profit takers held sway after the records seen on Friday.
A strong non-farm payrolls number eased some concerns in the market over the health of the US economy.
The S&P 500 briefly hit an all-time high following the jobs data, but was off a couple of points at 2180.5 as trading got underway.
The Dow Jones Industrial Average eased 18 to 18,524, while Nasdaq was 13 lower at 5,207.
Merck retreated after the big gains last week following the failure of rival Bristol-Myers Squibb’s (NYSE:BMY) immunotherapy drug Opdivo in a lung cancer trial.
That result has seemingly leaving the way clear for Merck’s Keytruda, which passed its trial. Merck (NYSE:MRK) eased 2% to US$62.47 and Bristol Myers fell 5% to US$60.37.
Delta Airlines (NYSE:DAL) was little changed at US$37.73 despite a power cut causing it to suspend flights worldwide and leave hundreds of passengers stranded around the world.
Talk of a production freeze by OPEC gave the oilers a boost with ExxonMobil and Chevron both rising by about 1%.
South Africa group Steinhoff continued its transatlantic bid spree with a bid for Mattress Firm Holding (NASDAQ:MFRM).
Steinhoff is offering US$64 per share or US$2.4bn in cash, sending shares in Mattress up by 114% to US$63.68.