* Yum shares fall alongside China sales
* Futures: Dow, Nasdaq flat, S&P up 0.2 pt
NEW YORK, Jan 8 (Reuters) - U.S. stock index futures were little changed in low volume on Tuesday ahead of the unofficial start of an earnings season expected to show sluggish corporate growth.
* Profits in the fourth quarter were expected to top lackluster results in the previous quarter, but analysts' current estimates are down sharply from where they were in October. Fourth-quarter earnings are expected to grow by 2.8 percent, according to Thomson Reuters data.
* S&P 500 futures were up 0.2 point and slightly 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 were also flat.
* Shares of Yum Brands Inc fell 5 percent to $64.50 in light premarket trading a day after the KFC parent warned sales in China, its top market, shrank more than expected in the fourth quarter.
* ConAgra Foods Inc priced a public offering of 8.1 million common shares at $29.75 per share, the foodmaker said on Monday. ConAgra closed at $30.17 during regular Monday trading.