U.S. stock index futures were mixed on Wednesday with Nasdaq lifted by blowout earnings from Apple late Tuesday as the focus shifting to results from four Dow components and other bellwethers including Morgan Stanley.

Apple Inc shares hit an all-time high in late trading on Tuesday after its quarterly results blew past expectations on the back of record iPhone sales, and the company gave a strong revenue forecast. Shares rose 5.3 percent to $257.50 in premarket trading on Wednesday.

Dow component United Technologies Corp posted a 20 percent rise in profit, ending a four-quarter streak of declines. Its shares closed at $74.20 on Tuesday.

Results from fellow Dow components Boeing Co , McDonald's Corp and AT&T Inc are also on tap.

S&P 500 futures fell 2.4 points but were slightly above fair value, a formula that evaluates pricing by taking into account interest rates, dividends and time to expiration on the contract. Dow Jones industrial average futures fell 29 points, and Nasdaq 100 futures added 4.75 points.

Morgan Stanley is due to report first-quarter results, with analysts looking for a profit of 57 cents per share, according to Thomson Reuters I/B/E/S. The results will be the first under new Chief Executive James Gorman and his reshuffled management team.

Other companies due to report include Wells Fargo & Co , Freeport-McMoRan Copper & Gold Inc and eBay Inc .

The International Air Transport Association estimated the shutdown of most European airports caused by a volcanic ash cloud cost airlines more than $1.7 billion in revenues.

U.S. stocks rose on Tuesday as oil prices lifted energy shares and investors were upbeat about the overall corporate profits recovery, even as some the results of some high-profile companies fell short of lofty expectations.

(Editing by Jeffrey Benkoe)