* Facebook director dumps stock
* Best Buy shares slump 10 pct
* Spanish bond yields ease
* Futures up: S&P 500 2.6 pts, Dow 24 pts, Nasdaq 8 pts
By Edward Krudy
NEW YORK, Aug 21 (Reuters) - U.S. stock index futures edged higher on Tuesday, with Wall Street set to make another run at a four-year high as equity markets continue to grind steadily higher on hopes that central banks will act in the near future to stimulate their economies.
The S&P 500 has risen nearly 3 percent so far in August. Much of those gains have come on a few outsized days while other days have seen small incremental gains. Volumes have been light as investors wait for central banks' meetings next month where policymakers are expected to take action to ease Europe's debt crisis and boost the economy.
"I am looking for new highs in the major indexes," said Wayne Kaufman, chief market analyst at John Thomas Financial in New York. "Overall there is no one major negative that's out there right now that people are scared of."
The perception of declining risks from the euro crisis has been a major factor behind equity gains. Yields at a Spanish short-term debt auction dived on Tuesday, while Europe's volatility index VSTOXX hit a one-month low, signaling a steady rise in investors' appetite for risk.
The S&P 500 needs to pass this year's high of 1,422.38 set in April to make a four-year intraday high. That would take the index back to May 2008. The index closed 1,418.13 on Monday.
"With no negative headlines dampening enthusiasm the market looks ahead to another milestone," said Andre Bakhos, director of market analytics at Lek Securities in New York. "That could easily be accomplished today."
S&P 500 futures rose 2.6 points and were above 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 rose 24 points, and Nasdaq 100 futures added 8 points.
Best Buy Co shares slumped 10 percent premarket. The company cut its fiscal-year profit outlook on Tuesday, citing lower expectations for industrywide sales and uncertainty about key product introductions, and the consumer electronics retailer suspended its share buybacks for the year.
Signs that the U.S. labor market is performing better than previously thought have also helped stocks.
European stocks rose, keeping a four-week rally alive, as investors bet the European Central Bank will soon start buying Spanish and Italian bonds to help lower their borrowing costs. The FTSEurofirst 300 rose 0.2 percent.
Facebook Inc director Peter Thiel sold roughly $400 million worth of shares in the Internet social networking company last week, cashing out most of his stake. The sale comes as Facebook shares lost 50 percent of their value since its IPO earlier this year. The shares fell 0.9 percent to $19.84 in premarket trade.
The chief executives of Apple Inc and Samsung Electronics Co Ltd have talked but did not settle the high-stakes patent dispute between the two electronics companies, a Samsung attorney said in court on Monday.
Citigroup Chief Executive Vikram Pandit has rejected the idea of big banks being split up, the Financial Times reported on Tuesday. Pandit said Citi, formed through mergers such as the acquisition of Travelers in 1998, had already gone back to the basics of banking, and had sold most of the units from that deal.
Global buyout fund KKR & Co L.P. has placed a bet on China's $38 billion youth apparel retail market, saying that it will acquire a stake in privately held retailer Novo Holdco Ltd for $30 million.
U.S. stocks closed flat on Monday after a six-week run of gains as the European Central Bank quashed a report on what strategy it may use in any market intervention to stem the region's debt crisis.