Stock futures pressured as ECB hopes give way to doubts

NEW YORK (Reuters) - Stock index futures were mixed on Thursday as doubts arose about when the European Central Bank may start buying bonds to tackle the bloc's crisis and how effective such a move can be.

However, Chinese economic data kept alive talk that central banks will intervene to support the global economy as annual growth in factory output slowed to its weakest in more than three years in July while annual consumer price inflation hit a 30-month low.

S&P 500 futures fell 1 point and were below 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 were unchanged and Nasdaq 100 futures added 3 points.

Nestle , the world's biggest food group, said first half results beat expectations and it expects pressure from the high prices of basic foodstuffs to ease in the second half of the year.

Several private equity firms that have been approached to join in a buyout of Best Buy are sitting on the fence, private equity sources said, citing the lack of a tangible plan by the retailer's founder Richard Schulze, and doubts about his ability to pull the deal off.

(Reporting by Rodrigo Campos)