* Twitter slumps after results
* Green Mountain surges on deal with Coca-Cola
* Initial claims data due
* Retailers report monthly sales
* Futures up: Dow 63 pts, S&P 7.5 pts, Nasdaq 15.75 pts
NEW YORK, Feb 6 U.S. stock index futures advanced on Thursday, ahead of a rate decision by the European Central Bank, as well as U.S. labor market data and the latest round of corporate earnings.
* The ECB, which announces its policy decision at 7:45 a.m. EST (1245 GMT), is largely expected to keep rates unchanged at its record low benchmark of 0.25 percent.
* U.S. weekly initial jobless claims are due at 8:30 a.m. (1330 GMT). Analysts expect 335,000 new filings, down from the prior week's 348,000.
* Twitter Inc shares tumbled 23 percent to $50.80 in premarket trade. The company reported its slowest pace of user growth in recent company history after the close on Wednesday, dimming hopes that the social media phenomenon could sustain its torrid pace of expansion.
* Green Mountain Coffee Roasters Inc surged 43.4 percent to $116 before the opening bell. Coca-Cola Co had bought a 10 percent stake in it for $1.25 billion and would help launch Green Mountain's new cold drink machine planned for release as soon as October. Shares of home beverage device maker SodaStream International dropped 8.1 percent to $32.88 in premarket trading.
* S&P 500 e-mini 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 gained 63 points and Nasdaq 100 futures added 15.75 points.
* As the U.S. Federal Reserve continues its efforts to wind down its stimulus measures, investors have turned their focus to fundamentals such as corporate earnings and economic data.
* However, many participants have wondered if recent soft data truly reflects the economy or is the result of a harsh winter, and are looking to Friday's payrolls report for a clearer indication of the economy's health.
* Investors will eye monthly sales results from retailers for signs of strength in consumer spending. Costco Wholesale Corp's January same-store sales beat market expectations, even as the warehouse club retailer recorded weak fuel prices and lower international sales in dollar terms.
* Dunkin' Brands Group Inc reported a 23 percent rise in quarterly profit, driven by higher growth in sales at its Dunkin' Donuts coffee and sandwich outlets. The company also boosted its quarterly dividend and announced a new $125 million share buyback plan.
* Aetna Inc, the third-largest U.S. health insurer, on Thursday said fourth-quarter profit rose due to the acquisition of Coventry Healthcare, and it forecast an increase in medical customers in its private Medicare business in 2014.
* European equities climbed in cautious trading ahead of rate decisions by central banks, lifted by reassuring earnings from major companies such as Alcatel-Lucent and AkzoNobel.
* Asian shares took a tentative step forward from five-month lows, with investors hoping the ECB and upcoming U.S. jobs data will calm nerves strained by a recent rout in emerging markets.