Stock index futures rose on Wednesday as continued strong earnings, including from Apple Inc
* Equities have struggled against a number of headwinds recently, including concerns about sovereign debt problems in the United States and Europe, but on Tuesday posted their best day since March, helped by strong results from such bellwethers as International Business Machines Corp
* Tech giant Apple late Tuesday posted third-quarter revenue that was far above expectations, helped by blockbuster sales of its iPhone, as well as its Asian business. The stock gained 4.5 percent to $393.80 in premarket trading.
* Yahoo Inc
* Earnings will continue to be in focus, with American Express Co
* Among the early reporting companies on Wednesday were Textron Inc
* Investors will also be looking for June existing home sales data, due at 10:00 EDT, which are seen rising from the previous month. On Tuesday, housing starts that were much stronger than expected contributed to the market's positive tone.
* S&P 500 futures rose 7.5 points and were 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 added 62 points and Nasdaq 100 futures rose 23 points.
* Ecolab Co
* The growing optimism over earnings season comes as market participants also had more confidence with the ongoing talks for a debt deal in the U.S. Markets gained momentum late in the day on Tuesday after President Barack Obama suggested progress was being made toward a $3.75 trillion deficit reduction deal centered around entitlement reform.
* The White House and Congress need an agreement that includes an increase in the federal debt ceiling by August 2 or the United States could default on its debt.
* Obama's comments, along with the earnings, sparked a sharp equity rally on Tuesday, with all indexes rising more than 1.6 percent and the Nasdaq climbing more than 2 percent.
(Editing by Chizu Nomiyama)