Stock futures edge lower after Alcoa results, outlook

U.S. stock index futures edged lower on Wednesday after Alcoa kicked off earnings season by warning of a slight slowdown in some markets, highlighting concerns about sluggish global growth, even as its quarterly results beat expectations.

* Stronger demand for aluminum products from airplane and automobile producers helped Alcoa Inc's third-quarter profit beat analysts expectations, but it scaled back its global aluminum consumption outlook for 2012, citing the slowdown in China. Alcoa shares lost 1.4 percent to $9 in light premarket trade.

* Analysts forecast third-quarter earnings of Wall Street's S&P 500 companies would fall 2.3 percent from the year-ago quarter, according to Thomson Reuters data, which would be the first drop in U.S. quarterly earnings in three years.

* Going against general declines was Yum Brands Inc , which gained 2.1 percent to $67.42 in premarket trading. The KFC parent company had raised its full-year outlook after sales in China held up, despite that nation's cooling economy.

* U.S. engine maker Cummins Inc lowered its 2012 forecast for a second time this year, citing delays in customer spending due to a weakening global economy, and said it would cut up to 1500 jobs.

* Chevron Corp , the second-largest U.S. oil company, warned that third-quarter profits would be "substantially lower" than in the previous quarter as a hurricane and maintenance curbed its oil and gas output and a fire hit its refining arm.

* Earnings from warehouse chain Costco Wholesale Corp were a bright spot; the company reported a 27 percent jump in fourth quarter profit, on higher sales and membership fees.

* Coming on the heels of a 2013 profit forecast that was cut last month, FedEx Corp said it plans to slash costs at its underperforming express air freight and services divisions, with profit improvements of $1.7 billion planned at those operations over the next four years.

* European shares were lower for a third straight session, hurt by expectations of weak corporate results that may weigh on equity markets into next month.

(Reporting by Chuck Mikolajczak; Editing by Bernadette Baum)