Apple, other tech earnings in focus on Wall Street

U.S. stocks were expected to open a touch weaker on Tuesday, as the second-quarter earnings season gets into full swing with the likes of Apple, Microsoft and Yahoo reporting this session.

In addition to the tech heavyweights, markets will also digest earnings from Verizon, Baker Hughs, Bank of NY Mellon and United Technologies to name a few.

Volatility in commodity markets is also likely to get some attention, with U.S. oil prices slipping back below the $50-a-barrel mark on the back of a stronger dollar and worries about a supply glut.

Gold prices, however, recovered about 1 percent to $1,107.49 an ounce after falling to five-year lows the previous session.

Read MoreTuesday focus: Commodities crush versus earnings

U.S. stocks closed mildly higher on Monday, with the tech-heavy Nasdaq hitting another record high.

"The bull market in the U.S. looks less appealing than in Europe right now," Alex Friedman, CEO at asset manager GAM Holding, told CNBC on Tuesday. "As an overall market, it's range-bound."

IBM reported earnings after the closing bell on Monday that fell short of expectations – news that could weigh on investor sentiment ahead of Apple earnings later on Tuesday.

Stock futures for the blue-chip Dow Jones industrial average were down about 21 points in early London trade.

IBM shares fell about 4 percent in extended trading on Monday after the tech firm posted second-quarter adjusted profit of $3.84 per share on $20.81 billion in sales. Those were both down 13 percent from the prior-year period.

Apple meanwhile is expected to post its earnings after the closing bell.

Analysts polled by Thomson Reuters are on average looking for sales growth of 32 percent to $49.3 billion. Earnings per share is seen increasing to $1.79 from $1.28 a year earlier.

Read MoreApple earnings: Can it weather the China storm?

In Europe, regional stock markets gave up early gains and moved into negative territory and Asian shares ended the day higher.

Japan's Toshiba Corp was in focus after the company's chief executive said he was stepping down on Tuesday after an independent investigation found he had been aware that the firm had inflated its profits for a number of years.

Toshiba shares, which have fallen more than 20 percent since the firm unveiled accounting irregularities in April, soared 6 percent in Tokyo.