Apple shares weigh on futures ahead of Fed

U.S. stock-index futures traded lower on Wednesday, amid of swathes of big-name earnings and a Federal Reserve policy decision.

Nasdaq 100 futures were off about 1 percent. Shares in Apple were down more than 8 percent in pre-market trade after the company reported quarterly earnings and revenue that missed analysts' expectations. Its guidance for the current quarter also missed forecasts.

Companies that reported quarterly results early in the day included Comcast, Boeing and United Technologies Corporation. Comcast is said to be in talks to acquire Dreamworks Animation in a $3 billion deal.

Facebook will post numbers after Wall Street closes.

Pending home sales data will be out on Wednesday, along with crude inventories.

WTI and Brent crude oil futures extended gains in Asia overnight, following a reported drop in U.S. inventories.

Total mortgage application volume decreased 4.1 percent last week on a seasonally adjusted basis from the previous week, according to the Mortgage Bankers Association.

The U.S. advance March goods trade deficit came in at $56.90 billion, narrowing from the $62.86 gap reported in the prior month.

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The Federal Open Market Committee (FOMC) rate decision for April is due at 2 p.m. ET. No interest rate hike is expected, although the possibility of one in June may be flagged.

"The o/n (overnight) Fed funds rate will be held steady and the focus shall be on the continued strength in the labor markets, while there shall be continued discussions regarding the weakness in the economies abroad and thus the need to hold policy steady," market commentator, Dennis Gartman, said in The Gartman Letter on Tuesday.

In other news, presidential candidates, Donald Trump and Hillary Clinton, pulled ahead of rivals in Tuesday's primary contests in Pennsylvania, Maryland, Connecticut, Rhode Island and Delaware.

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Disclosure: Comcast is the parent company of NBCUniversal and CNBC.