* Euro zone crisis "not over," Weidmann says
* Shares of Yum Brands up on China restaurant sales
* Retailer Costco posts stronger-than-expected profit
* Futures off: Dow 27 pts, S&P 3.3 pts, Nasdaq 7.5 pts
By Chuck Mikolajczak
NEW YORK, March 12 (Reuters) - U.S. stock index futures dipped on Tuesday as investors appeared set to lock in profits after a seven-session string of gains and the Bundesbank's chief warned the euro zone's crisis has not ended.
Both the Dow and benchmark S&P index have rallied for seven consecutive sessions, with the Dow setting another record high on Monday and the S&P within 10 points of its all-time closing high of 1,565.15 set on Oct. 9, 2007.
Any pullback may be short-lived as investors have been using recent dips as a buying opportunity.
Sounding a note of caution in Europe, Jens Weidmann, who is a member of the European Central Bank's governing council, said the euro zone's "crisis is not over despite the recent calm on financial markets," adding that the region's economic stability remains on shaky ground.
Investors' confidence in U.S. equities has grown, leading to a gain of more than 10 percent for the year by the Dow and more than 9 percent by the S&P. Signs of improvement in the economy and the Federal Reserve's quantitative easing have helped to drive the gains.
The boost in confidence was reflected in the Chicago Board Options Exchange Volatility Index. Wall Street's so-called fear gauge dropped to its lowest level since February 2007 on Monday.
"The market has gotten awfully complacent here, and there doesn't seem to be enough to really push us out to substantial new highs," said Rick Meckler, president of investment firm LibertyView Capital Management in Jersey City, New Jersey.
"But the confidence investors have that there is no real setback coming has left us just drifting higher and higher almost every day."
S&P 500 futures fell 3.3 points 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 lost 27 points, and Nasdaq 100 futures shed 7.5 points.
Retailer Costco Wholesale Corp posted a 39 percent increase in quarterly profit, beating expectations, on increasing sales, membership fees and a tax benefit related to a special cash dividend. Costco shares gained 1.5 percent to $103.94 in premarket trade.
Yum Brands Inc advanced 6.2 percent to $72.05 in premarket trade after the parent company of the KFC restaurant chain reported an unexpected rise in February sales in China.
European shares consolidated near 4-1/2 year highs as a rally in miner Antofagasta was offset by steep falls in the real estate sector and disappointing UK economic data.
Asian shares eased but growing confidence in the U.S. economy underpinned risk sentiment.