* Yum shares fall alongside China sales
* Sears says CEO to step down, shares rise
* Futures: Dow flat, S&P off 0.8 pt, Nasdaq down 0.5 pt
NEW YORK, Jan 8 (Reuters) - U.S. stock index futures were little changed in low volume on Tuesday before the unofficial start of the earnings season, which is expected to show sluggish corporate growth.
Profits in the fourth quarter were expected to top the previous quarter's lackluster results, but analysts' current estimates are down sharply from where they were in October. Quarterly earnings are expected to grow by 2.8 percent, according to Thomson Reuters data.
German data showed industrial orders fell more than forecast in November due to a sharp drop in demand from abroad, reinforcing concerns that Europe's largest economy may have contracted in the fourth quarter of 2012.
"I'm surprised futures are holding up, given the relative disappointment that German data showed, but I think all eyes are on the beginning of earnings season," said Kim Forrest, senior equity research analyst at Fort Pitt Capital Group in Pittsburgh.
Monsanto Co, Apollo Group and Dow component Alcoa Inc start the quarterly season.
Monsanto shares rose 3.2 percent to $99 after announcing first-quarter results and the company's outlook.
"Alcoa is not a huge bellwether," Forrest said. Investors are now focused more on companies' performance than on macroeconomic factors, so "we should be kind of flat until we get some company-oriented news," she said.
S&P 500 futures were off 0.8 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 fell half a point.
Shares of Yum Brands Inc fell 5 percent to $64.50 in premarket trading a day after the KFC parent warned sales in China shrank more than expected in the fourth quarter.
Sears Holdings shares rose 5.5 percent to $45.27 in light premarket trading a day after the company said its chief executive will step down for family health reasons. The U.S. retailer also reported a 1.8 percent decline in quarter-to-date sales at stores open at least a year.
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.