U.S. stock index futures pointed to a flat open on Wednesday, held back by worries over the Sino-U.S. trade war, while Apple shares moved higher ahead of the expected launch of three new iPhone models.
Shares of Apple rose 0.3 percent in premarket trading, ahead of an event at 1 p.m. ET (1700 GMT).
Wall Street is more focused on the price hikes for the latest line of iPhones as Apple looks to sustain revenue growth from its signature product even as global demand for smartphones plateau.
Shares of energy companies were among the top gainers on the S&P 500 as oil prices hovered near $80 per barrel on growing concern over global supply.
Chevron's 1.1 percent gain was the most among the components of the Dow Industrials trading premarket, partly helped by HSBC's upgrade for the stock.
Lingering worries over an escalation in trade dispute got a fresh impetus on Tuesday after President Donald Trump said Washington was taking a tough stance with China, cementing expectations that fresh levies on Chinese exports will soon be announced.
More than 60 U.S. industry groups are launching a coalition to take the fight against Trump's tariffs public.
"These business groups aligning against the trade war is something Trump should take into consideration," said Peter Cardillo, chief market economist at Spartan Capital Securities in New York.
"But if he doesn't, then we could be heading towards some serious trouble and the longer the spat continues, the more concerning it is to markets."
At 8:48 a.m. ET, Dow e-minis were down 7 points, or 0.03 percent. S&P 500 e-minis were down 2 points, or 0.07 percent and Nasdaq 100 e-minis were down 6.75 points, or 0.09 percent.
Gilead Sciences rose 4.2 percent after its rheumatoid arthritis drug, being developed jointly with Galapagos NV, met the main goal of a study.
Nielsen was up 4.2 percent after the TV ratings provider said it will expand a review of strategic options to include a sale of the entire TV ratings company.
Companies related to memory chips came under pressure after Goldman Sachs warned of lower prices for such chips due to an oversupply of DRAM and NAND chips.
Micron fell 4.5 percent after Goldman Sachs cut its rating on the stock. Seagate Technology dropped 1.6 percent and Western Digital 1.8 percent.
Chip equipment makers Lam Research, Applied Materials, KLA Tencor and ASML Holding fell between 1.8 percent and 3 percent.
The Federal Reserve's "Beige Book," a summary of the state of U.S. business across the central bank's 12 regional districts for the month of August, is expected at 2 p.m.