US SMALL/MIDCAPS-Stocks end lower; profit warnings a worry

NEW YORK, Oct 5 (Reuters) - Small- and mid-capitalizationstocks closed flat to lower o n Friday, with shares of Zynga

falling 12 percent after it slashed its 2012 outlookfor a second time.

A spate of recent profit warnings from companies have addedto anxiety about the upcoming corporate earnings period.Standard & Poor's 500 earnings kick off next week, with resultsfrom Alcoa , shortly before the small- and mid-cap reportsbegin in earnest.

Shares of Zynga fell 12 percent to $2.48 after the socialgames maker cut its 2012 outlook for a second time on the poorperformance of its live Internet games and the writeoff of anacquisition.

Shares of Facebook , which derives over a tenth of itsrevenue from fees paid by Zynga, fell 4.7 percent to $20.91.

Earlier this week, network gear maker Adtran saidseasonality and a weak spending environment may lead to a fallin fourth-quarter revenue. Its shares slipped 2.9 percent to$16.19.

Doug Cote, chief market strategist of ING InvestmentManagement in New York, warned investors against getting toopessimistic on earnings.

"There certainly is a risk of negative corporate earningsbut there are mitigating factors right now, and the biggestfactor is the unprecedented global monetary stimulus thathappened over the past few weeks. And what I see is that isstarting to have a positive influence," he said.

Among some positive reports on the economy lately, data onFriday showed the U.S. jobless rate unexpectedly dropped to 7.8percent in September.

The S&P MidCap 400 index was up 0.02 percent whilethe S&P SmallCap 600 index was down 0.2 percent. Incomparison, the benchmark S&P 500 was down 0.03 percent.

(Reporting By Caroline Valetkevitch; Editing by Diane Craft)

((caroline.valetkevitch@thomsonreuters.com)(+1 646 2236393)(Reuters Messaging:caroline.valetkevitch@thomsonreuters@reuters.net))