U.S. stock index futures pointed to a higher open for Wall Street on Wednesday, extending the previous session's sharp gains and ahead of the start of third-quarter earnings season, with aluminum group Alcoa the first in line.

* Alcoa is expected to report a drop of $0.11 in earnings per share in the third quarter, compared with a rise of $0.33 in the same period last year. Alcoa shares in Frankfurt put on 1.3 percent.

Costco Wholesale Corp beat analyst expectations after posting a lower-than-expected fourth-quarter profit, suggesting an improvement in the weak U.S. retail environment.

Costco shares in Frankfurt were up 1.8 percent.

Monsanto, the world's biggest seed company, will also report results on Wednesday.

Bank of America Corp's board has narrowed the list of company candidates to replace retiring Chief Executive Kenneth Lewis to the bank's chief risk officer and its consumer and small-business banking chief, the Wall Street Journal reported on its website on Tuesday.

Amazon.com Inc is to introduce Kindle, its wireless electronic reader, to over 100 countries, including China and most of Europe, intensifying a battle for the burgeoning digital book market.

AT&T Inc will open its third-generation wireless network to third-party Internet voice applications on Apple Inc's iPhone, clearing the way for services such as Skype.

Impax Laboratories Inc will be able to sell a generic version of Astellas Pharma's <4503.T> Flomax prostate drug one month ahead of its U.S. patent expiry under a settlement agreement.

French media giant Vivendi SA , would like to sell its 20 percent stake in NBC Universal, but at the right price, Bloomberg reported on Tuesday, citing a person familiar with the discussions.

GE owns 80 percent of NBC Universal and, under terms of an agreement dating back to 2004, would have the right of first refusal to pick up the other 20 percent should Vivendi exercise its option to sell the stake this year.

Insurance risk specialist Verisk Analytics Inc raised $1.88 billion on Tuesday in the biggest IPO by a U.S. company since March 2008, after pricing its shares at a higher-than-expected $22 each.

Citigroup Inc is weighing options including a possible sale of its Phibro commodities unit, which has been controversial for a star trader's large pay package, a source familiar with the matter said.

U.S. government-controlled mortgage finance companies Freddie Mac and Fannie Mae are working on a program to help independent mortgage banks get access to short-term credit needed to make home loans, the Wall Street Journal said, citing people familiar with the matter.

American Express Co President Alfred Kelly will leave the company next April, the credit card firm said on Tuesday, one day after announcing the executive's departure.

Kansas City Fed President Thomas Hoenig said while the U.S. economy is clearly rebounding, it is too soon to begin to withdraw the Federal Reserve's massive support.

A federal grand jury is investigating whether Hilton Worldwide, owned by Blackstone Group , and some of its former executives should face criminal charges for allegedly stealing tens of thousands of pages of confidential documents from rival Starwood Hotels & Resorts , the Wall Street Journal said.

U.S. stocks rose on Tuesday amid signs the global economy was recovering and optimism that corporate earnings reports will beat expectations.

The Dow Jones industrial average <.DJI> was up 131.50 points, or 1.37 percent, at 9,731.25. The Standard & Poor's 500 Index <.SPX> was up 14.26 points, or 1.37 percent, at 1,054.72. The Nasdaq Composite Index <.IXIC> was up 35.42 points, or 1.71 percent, at 2,103.57.

(Reporting by Dominic Lau; editing by Simon Jessop)